The 76th edition of the Skeptics' Circle has been released, it's being hosted over at Aardvarchaeology. My favorite entries are: Coffee House Poetry's fun atheistic rant and Whiskey Before Breakfast's entry on how the 20th century certainly wasn't the bloodiest in history (on a per capita basis at least).
Oh... I almost forgot about the latest edition of Encephalon.
Thursday, December 20, 2007
Thursday, December 13, 2007
Open access
I recently moved between universities: from the University of Cape Town to the University of Kwa-Zulu Natal. Unfortunately, my new university is a bit under resourced and doesn't have institutional access to quite a few journals. (Including fairly prominent ones). It was then (and particularly when I started blogging) that I realized just how frustrating, annoying and counter-productive the barriers to accessing knowledge really is. I suspect many people who access the web mainly from their well-financed institutions also fail to realize just what an issue this can be.
The bottom line with respect to open access is this: scholars do research, peer review it and even edit the journals, all without expecting to be paid. (Researchers get paid by their institutions, of course, and part of their job description is usually producing academic papers - the point is scholars don't expect to be paid by journals for their work). The publishing houses, however, charge exorbitant prices for access to their scholarly journals and the result is a high financial barrier. There was a time the arrangement between the scholarly community and publishers made sense: before the internet was created, when journals had to be printed in order to be distributed. Since it's now possible to distribute journal articles digitally at extremely low cost, this relationship has become outdated and unnecessary. As the Budapest Open Access Initiate put it, the internet makes possible :
What to do? If you are an author, self-archive and consider publishing in open access journals. (Opening access, by the way, seems to increase an article's readership and impact). Everybody else, spread the word (e.g.: join my group on Facebook: "Support Open Access"), support open access journals (read them, cite them) and sign the Budapest Open Access Initiative if you haven't done so already.
P.s. Yes, I realize I'm late on the bandwagon.
The bottom line with respect to open access is this: scholars do research, peer review it and even edit the journals, all without expecting to be paid. (Researchers get paid by their institutions, of course, and part of their job description is usually producing academic papers - the point is scholars don't expect to be paid by journals for their work). The publishing houses, however, charge exorbitant prices for access to their scholarly journals and the result is a high financial barrier. There was a time the arrangement between the scholarly community and publishers made sense: before the internet was created, when journals had to be printed in order to be distributed. Since it's now possible to distribute journal articles digitally at extremely low cost, this relationship has become outdated and unnecessary. As the Budapest Open Access Initiate put it, the internet makes possible :
Open access is good for everyone except those companies with a vested interest in the status quo. We should not let a special interest group stand in the way of a great public good being realized.world-wide electronic distribution of the peer-reviewed journal literature and completely free and unrestricted access to it by all scientists, scholars, teachers, students, and other curious minds. Removing access barriers to this literature will accelerate research, enrich education, share the learning of the rich with the poor and the poor with the rich, make this literature as useful as it can be, and lay the foundation for uniting humanity in a common intellectual conversation and quest for knowledge.
What to do? If you are an author, self-archive and consider publishing in open access journals. (Opening access, by the way, seems to increase an article's readership and impact). Everybody else, spread the word (e.g.: join my group on Facebook: "Support Open Access"), support open access journals (read them, cite them) and sign the Budapest Open Access Initiative if you haven't done so already.
P.s. Yes, I realize I'm late on the bandwagon.
Wednesday, December 12, 2007
My second BMJ rapid response gets published
BMJ have published my reply to the authors' rapid response to my criticisms, it can be found here. There are a few fairly minor differences between my blog and my rapid response but the gist is the same. I tried hard to be conciliatory. I suspect I failed miserably.
Rapid human evolution
It is commonly accepted among evolutionary psychologists (at least in the Santa Barbara school*) that "our modern skulls house a stone age mind". As Tooby & Cosmides put it,
*The Santa Barbara school of evolutionary psychology is the best known type of EP, its foremost exponents are Leda Cosmides, John Tooby, Donald Symons, David M. Buss, Steven Pinker, Margo Wilson and Martin Daly. (It's so called because Symons, Tooby & Cosmides are at UC Santa Barbara).
natural selection... takes a long time to design a circuit of any complexity. The time it takes to build circuits that are suited to a given environment is so slow it is hard to even imagine -- it's like a stone being sculpted by wind-blown sand. Even relatively simple changes can take tens of thousands of years. The environment that humans -- and, therefore, human minds -- evolved in was very different from our modern environment. Our ancestors spent well over 99% of our species' evolutionary history living in hunter-gatherer societies. That means that our forebearers lived in small, nomadic bands of a few dozen individuals who got all of their food each day by gathering plants or by hunting animals.Similarly, Edward Hudgens explains,
Evolutionary psychologists downplay the possibility of significant cognitive evolution in the 10,000 or so years since the advent of agriculture (a period of time known as the Holocene) for reasons of both science and political correctness. Scientifically, 10,000 years (500 generations) is not much time for natural selection to act, and it certainly is not enough time to evolve new, complex adaptations—sophisticated mechanisms coded for by numerous genes.New research just released in PNAS has the potential to undermine these claims fatally. John Hawks and his colleagues argue that human evolution accelerated very rapidly in the last 40,000 years. The abstract:
Genomic surveys in humans identify a large amount of recent positive selection. Using the 3.9M HapMap SNP dataset, we found that selection has accelerated greatly during the last 40,000 years. We tested the null hypothesis that the observed age distribution of recent positively selected linkage blocks is consistent with a constant rate of adaptive substitution during human evolution. We show that a constant rate high enough to explain the number of recently selected variants would predict (1) site heterozygosity at least tenfold lower than is observed in humans, (2) a strong relationship of heterozygosity and local recombination rate, which is not observed in humans, (3) an implausibly high number of adaptive substit utions between humans and chimpanzees, and(4) nearly 100 times the observed number of high-frequency LD blocks. Larger populations generate more new selected mutations, and we show the consistency of the observed data with the historical pattern of human population growth. We consider human demographic growth to be linked with past changes in human cultures and ecologies. Both processes have contributed to the extraordinarily rapid recent genetic evolution of our species.(See also: John Hawks's two blog entries on his study, and Reuters' report)
*The Santa Barbara school of evolutionary psychology is the best known type of EP, its foremost exponents are Leda Cosmides, John Tooby, Donald Symons, David M. Buss, Steven Pinker, Margo Wilson and Martin Daly. (It's so called because Symons, Tooby & Cosmides are at UC Santa Barbara).
Tuesday, December 11, 2007
Active parents raise active children: the authors reply
Recently, I wrote a rather scathing blog entry (see also my follow-up post) and a more measured "rapid response" to a BMJ (British Medical Journal) article that argued parents socialize their children into being physically either more active or more sedentary. Now the authors have replied to my criticism with a rapid response of their own. (Actually, the response was published almost a week ago - oh the dangers of going on holiday!). Suffice it to say I don't think Mattocks et. al. have neither met my criticism or understood it fully, so I'm going to respond to them both here and at the BMJ website. (Submissions to BMJ's rapid response system aren't peer-reviewed but are approved by an editor, so there's no guarantee my response will in fact be published. I'll link to my response if it does get published).
A quick recap of the study: the authors (Mattocks et. al., 2007) wanted to determine which early life variables (before age 5) affected the physical activity of children at ages 11-12 (which was objectively measured with accelerometers). They found that (among other things) "children are slightly more active if their parents are active early in the child's life and suggest "helping parents to increase their physical activity... may promote children's activity." It's clear from the quotations (and the rest of the study) that the authors were thinking solely in terms of socialization. As I pointed out in my critical blog entry (which I recommend you read if you haven't done so), there's an obvious possible confound here: genetics. Since (1) all behavioral traits are heritable (Turkheimer, 2000) and (2) children inherit 50% of their genes from each parent, "genetic factors are always possible confounds when relating parenting style (or other parental behavior) to outcomes in children". Consequently, because genetic factors were not controlled for, Mattock's et. al.'s study does not distinguish between the relevant possible causal hypotheses and therefore fails to add very much to our knowledge.
The authors' reply to my criticism, I think, amounts to the following: 'controlling for genetic factors is really hard' (first paragraph), and (2) 'not all the hypotheses we tested are confounded by genetic factors' (most of the second paragraph). Let's take these replies in turn. The literature about the determinants of physical activity is certainly not one of my specialities so I don't have an opinion about whether or not it's possible to control for genetics at the present time. Let's grant, for argument's sake, that Mattocks et. al. are correct: that it's not possible to control for genetic factors. What follows? Does assuming this proposition at all support the truth of their finding concerning the link between active parents and active children? Clearly not - the fact that we cannot control for a confound manifestly (and unfortunately) does not make it causally inert. Because genetics is a possible confound (something Mattocks et. al. do not dispute in their reply), we simply can't draw a conclusion one way or another because, to repeat, their data fails to distinguish between the relevant alternative causal hypotheses. I note furthermore that Mattocks et. al. seem to have been intellectually careless - they don't seem to have considered genetic factors as possible confounds when designing the study at all. Firstly, electronic text-searches confirm my impression from reading their paper: they fail even to mention genetics. Secondly and damningly, their paper does contain a section entitled "Possible confounders" but it does not list genetics as a possible instance.
Mattocks et. al. are correct in saying that not all the variables they considered are possibly confounded by genetics. I focused on a subset of their variables and findings because I found the study through this ScienceDaily article (title: "Active Parents Raise Active Children") and because the authors themselves emphasize the correlation (what they regard as causation) between maternal physical activity during pregnancy and early life and children's physical activity later in life (see the conclusion of the abstract). Furthermore, it seems a majority of the study's positive findings are at least possibly confounded by genetics, even if in some cases a particularly plausible causal mechanism is absent. (The sum total of the positive findings were that activity at 11-12 was 'modestly associated with': "mother's body mass index before pregnancy, parents' smoking status during pregnancy, mother's age at birth of the child, mother's physical activity, parity, and season of birth.")
In short, genetics is a possible confound (a fact that remains unaltered whether or not it's possible to control for it), but, despite this, the authors didn't even try to control for it and happily drew causal conclusions in the absence of controls. My criticisms stand.
Bibliography
Mattocks, C., Ness, A., Deere, K., Tilling, K., Leary, S., Blair, S.N., Riddoch, C. (2007). Early life determinants of physical activity in 11 to 12 year olds: cohort study. BMJ (British Medical Journal). DOI: 10.1136/bmj.39385.443565.BE
Turkheimer, E. (2000) "Three Laws of Behavior Genetics and What They Mean," Current Directions in Psychological Science, 9(5): 160-164.
A quick recap of the study: the authors (Mattocks et. al., 2007) wanted to determine which early life variables (before age 5) affected the physical activity of children at ages 11-12 (which was objectively measured with accelerometers). They found that (among other things) "children are slightly more active if their parents are active early in the child's life and suggest "helping parents to increase their physical activity... may promote children's activity." It's clear from the quotations (and the rest of the study) that the authors were thinking solely in terms of socialization. As I pointed out in my critical blog entry (which I recommend you read if you haven't done so), there's an obvious possible confound here: genetics. Since (1) all behavioral traits are heritable (Turkheimer, 2000) and (2) children inherit 50% of their genes from each parent, "genetic factors are always possible confounds when relating parenting style (or other parental behavior) to outcomes in children". Consequently, because genetic factors were not controlled for, Mattock's et. al.'s study does not distinguish between the relevant possible causal hypotheses and therefore fails to add very much to our knowledge.
The authors' reply to my criticism, I think, amounts to the following: 'controlling for genetic factors is really hard' (first paragraph), and (2) 'not all the hypotheses we tested are confounded by genetic factors' (most of the second paragraph). Let's take these replies in turn. The literature about the determinants of physical activity is certainly not one of my specialities so I don't have an opinion about whether or not it's possible to control for genetics at the present time. Let's grant, for argument's sake, that Mattocks et. al. are correct: that it's not possible to control for genetic factors. What follows? Does assuming this proposition at all support the truth of their finding concerning the link between active parents and active children? Clearly not - the fact that we cannot control for a confound manifestly (and unfortunately) does not make it causally inert. Because genetics is a possible confound (something Mattocks et. al. do not dispute in their reply), we simply can't draw a conclusion one way or another because, to repeat, their data fails to distinguish between the relevant alternative causal hypotheses. I note furthermore that Mattocks et. al. seem to have been intellectually careless - they don't seem to have considered genetic factors as possible confounds when designing the study at all. Firstly, electronic text-searches confirm my impression from reading their paper: they fail even to mention genetics. Secondly and damningly, their paper does contain a section entitled "Possible confounders" but it does not list genetics as a possible instance.
Mattocks et. al. are correct in saying that not all the variables they considered are possibly confounded by genetics. I focused on a subset of their variables and findings because I found the study through this ScienceDaily article (title: "Active Parents Raise Active Children") and because the authors themselves emphasize the correlation (what they regard as causation) between maternal physical activity during pregnancy and early life and children's physical activity later in life (see the conclusion of the abstract). Furthermore, it seems a majority of the study's positive findings are at least possibly confounded by genetics, even if in some cases a particularly plausible causal mechanism is absent. (The sum total of the positive findings were that activity at 11-12 was 'modestly associated with': "mother's body mass index before pregnancy, parents' smoking status during pregnancy, mother's age at birth of the child, mother's physical activity, parity, and season of birth.")
In short, genetics is a possible confound (a fact that remains unaltered whether or not it's possible to control for it), but, despite this, the authors didn't even try to control for it and happily drew causal conclusions in the absence of controls. My criticisms stand.
Bibliography
Mattocks, C., Ness, A., Deere, K., Tilling, K., Leary, S., Blair, S.N., Riddoch, C. (2007). Early life determinants of physical activity in 11 to 12 year olds: cohort study. BMJ (British Medical Journal). DOI: 10.1136/bmj.39385.443565.BE
Turkheimer, E. (2000) "Three Laws of Behavior Genetics and What They Mean," Current Directions in Psychological Science, 9(5): 160-164.
Monday, December 10, 2007
Race and IQ
A brouhaha is raging at the moment about race and IQ. James Watson started it off when he was quoted as saying he was "inherently gloomy about the prospect of Africa" because "all our social policies are based on the fact that their intelligence is the same as ours - whereas all the testing says not really". Then William Saletan over at Slate added fuel to the fire when he argued in a series of posts that Watson was supported by the scientific evidence. Saletan's claims were soon debunked by several people - most notably by Cosma Shalizi, Stephen Metcalf, and Richard Nisbett. (Saletan issued a semi-mea culpa about not realizing just how biased one of the journals he relied upon really was).
Now, the always fantastic and worth-reading Malcolm Gladwell has entered the debate with the release of his latest New Yorker article. The article is highly recommended - if you don't have the time or the patience to read all the articles I link to above, simply read Gladwell's contribution. It's a fine gloss.
Now, the always fantastic and worth-reading Malcolm Gladwell has entered the debate with the release of his latest New Yorker article. The article is highly recommended - if you don't have the time or the patience to read all the articles I link to above, simply read Gladwell's contribution. It's a fine gloss.
Friday, December 7, 2007
75th Meeting of the Skeptics' Circle
The 75th Skeptics' Circle blog carnival is out; and it includes one of my entries. (Which marks the loss of my blog carnival virginity...)
By the way, I'm on holiday at the moment and my access to the internet is pretty limited. I doubt I'll blog much in the next week.
By the way, I'm on holiday at the moment and my access to the internet is pretty limited. I doubt I'll blog much in the next week.
Tuesday, December 4, 2007
Encephalon #37
The latest edition of the psychology/AI/neuroscience/cog sci blog carnival, Encephalon, was just published. This time round it's being hosted over at A Blog Around the Clock. There are quite a few entries well worth checking out; my favorite was The Phineas Gage Fan Club report on a recent study on the influence of snap facial judgments on voting behavior.
Video: Evo-Devo in 60 seconds
Scientific American recently launched an interesting new vodcast, Instant Egghead, to accompany their 60 Second Science stable of podcasts. As you might have guessed, Instant Egghead explains various scientific concepts, theories or ideas in 60 seconds (tagline: "Explain Big Ideas. Fast.") . The two previous episodes covered Dark Matter and Moore's law, respectively; Episode 3 (embedded below, or click here to go to the SciAm site) is on Evo-Devo:
What I blog
In my very first entry, "Welcome", I said my blog:
I hope you'll keep reading! (You few...)
will consist almost entirely of my irregular musing and reflections on recent (and sometimes not so recent) published academic papers in evolutionary and social psychology. Occasionally I might indulge myself by venturing further afield, probably mainly into political science. I may even sometimes fail to take myself seriously and blog about something other than a specific academic paper.I now realize, however, that I underestimated just how powerless I am in the face of my very wide interests. So I've given up - I'm no longer even going to try restraining myself from blogging about issues that interest me. Basically, this means I won't try keeping to evolutionary and social psychology anymore. (Not that I have been anyway). Although the majority of the content here will be related to psychology, the scope of the blog is now (officially, instead of de facto) broader. I'll have occasional entries on biology, neuroscience, scientific skepticism, medicine, cognitive science and whatever else strikes my fancy really. Don't fear however: this will remain (a) a science blog (i.e. I won't start ranting about politics or discuss metaphysics) , (b) an academic blog (i.e. I won't start telling you what I ate for breakfast) and (c) a blog mainly about human behavior (i.e. I'll blog about other topics to the extent to which it impacts on our understanding of human behavior).
I hope you'll keep reading! (You few...)
Monday, December 3, 2007
News flash!
Updated: more links, embedded video.
Apparently, hormone fluctuations may be responsible for many mood disturbances in women! And, in other news, oceans contain water! Mountains are made of rock! Species evolve over time! I haven't actually read the articles this press release is based on (not my field), but I'm assuming they had more interesting findings. Hopefully...
More seriously, a new study in Current Biology has found that young chimpanzees have a better numerical working memory than adult humans beings. The abstract:
(See also the ScienceDaily press release, the Nature News writeup, the New Scientist article and Kyoto University's extensive collection of videos from the study).
Apparently, hormone fluctuations may be responsible for many mood disturbances in women! And, in other news, oceans contain water! Mountains are made of rock! Species evolve over time! I haven't actually read the articles this press release is based on (not my field), but I'm assuming they had more interesting findings. Hopefully...
More seriously, a new study in Current Biology has found that young chimpanzees have a better numerical working memory than adult humans beings. The abstract:
Chimpanzee memory has been extensively studied. The general assumption is that, as with many other cognitive functions, it is inferior to that of humans; some data, however, suggest that, in some circumstances, chimpanzee memory may indeed be superior to human memory. Here we report that young chimpanzees have an extraordinary working memory capability for numerical recollection — better even than that of human adults tested in the same apparatus following the same procedure.New Scientist magazine has a great little video on the study, it's embedded below (or click here to go directly to the video at YouTube):
(See also the ScienceDaily press release, the Nature News writeup, the New Scientist article and Kyoto University's extensive collection of videos from the study).
Friday, November 30, 2007
Hypnopompia, or, How I Learnt to Stop Belittling True Believers and Love Skepticism
I recently had a very vivid hypnopompic hallucination, what follows is my account of it. This post is something of a departure from the usual theme and tone of this blog, but since I plan to do some research into hypnopompia and hypnogogia early next year (probably with accompanying blog entries), I figured I’d write out my experience before I forget too many details.
Hypnogogia and hypnopompia are hallucinations that occur as you’re falling asleep or waking up, respectively, and are accompanied by sleep paralysis. In other words, they’re hallucinations that occur between sleep and wakefulness (or vice versa) and, while you’re hallucinating, you can’t move because you’re paralyzed. While sleep paralysis is entirely desirable while you’re asleep (acting out dreams isn’t good for one’s health I’m guessing), it is possible to be semi-awake and mostly aware of your surroundings while still paralyzed. Surprisingly, sleep paralysis is quite common (about 25-40% of people report experiencing it) and, although incidence seems to vary across cultures, it’s found worldwide (Cheyne, Rueffer, & Newby-Clark, 1999). Importantly, sleep paralysis is not always accompanied by hallucinations, about 30% of respondents in one survey said they had experienced sleep paralysis without hallucinations. Indeed, I’ve experienced sleep paralysis (sans hallucinations) probably half a dozen times or so and was never bothered by them much. (On one occasion I got rather frustrated though – I was awake and kept trying and trying to move but couldn’t. In retrospect, I’m a bit perplexed why it didn’t bother me more).
Around 3 a.m. on November 23rd, I woke up and heard my sister Liana’s voice. At first I thought I was back in Chester House in Cape Town (where I lived with Liana for ~ 2 years, in a bachelor’s flat) but then the voice started angrily lecturing me and telling me details of the dream I just had. (Probably due to sleep inertia, I don't now remember what I dreamt, but I distinctly recall the voice referring to minute details of my dream). This went on for about 5 minutes and as I slowly became aware of where I was - about 1,500km away from where Liana lives - I realized the voice was disembodied and became more and more frightened. I must emphasize, in fact, that the word “frightening” doesn’t come near to doing justice to the feeling. It was numbingly scary, petrifying, bloodcurdlingly terrifying.
And this, remember, was my sister’s voice — not something I’m scared of under normal conditions. Other people who have these hallucinations report not only hearing things, but experience visual, tactile and proprioceptive hallucinations. They report seeing old hags, demons, aliens, ghosts or other malevolent beings or report experiencing floating or falling sensations and so on. The fact that I just heard my sister's voice makes me suspect I had a fairly mild hallucination; I can only imagine how much more frightening it must be to see, say, an alien next to your bed while you're supine and paralyzed.
That brings me to my subtitle: "How I Learnt to Stop Belittling True Believers and Love Skepticism". For me, having this experience has really driven home the argument, made most forcefully by Carl Sagan and Joe Nickell, that it's a false dichotomy to think people who have paranormal experiences are either lying or crazy. There's a third alternative: they're having genuine experiences but then interpret the experiences incorrectly. That is, people really do experience what looks for all the world like an alien standing over their bed — but it's not really an alien, it's a phantom in the brain. And that's why I've learnt to love skepticism (even more): as soon as I woke up and got over my sleep inertia, I realized what had happened and was no longer afraid. My sister was due to give birth, so she was in my thoughts; I knew what sleep paralysis was, having experienced it before, and I knew about hypnopompic and hypnogogic hallucinations from The Skeptics Guide to the Universe podcast. (Thanks guys). So as soon as I thought about it clearly, I knew what had happened, could place my experience in perspective and I was thus saved from further negative emotions and a silly ontology.
My experience also made me realize just how compelling seemingly paranormal experiences can be. It's completely understandable that someone who regularly has hypnogogic hallucinations, lacks training in skeptical or critical thinking, knows nothing about neuroscience, and who is immersed in a popular culture full of references to paranormal entities will interpret such experiences as genuinely paranormal events. Belittling the experiences of the true believers in the paranormal, I now believe, is not appropriate — they deserve our sympathy, not our ridicule.
Links
Cheyne, J. A., Rueffer, S. D., and Newby-Clark, I. R. (1999) “Hypnagogic and Hypnopompic Hallucinations during Sleep Paralysis: Neurological and Cultural Construction of the Night-Mare,” Consciousness and Cognition, 8: 319–337
Hypnogogia and hypnopompia are hallucinations that occur as you’re falling asleep or waking up, respectively, and are accompanied by sleep paralysis. In other words, they’re hallucinations that occur between sleep and wakefulness (or vice versa) and, while you’re hallucinating, you can’t move because you’re paralyzed. While sleep paralysis is entirely desirable while you’re asleep (acting out dreams isn’t good for one’s health I’m guessing), it is possible to be semi-awake and mostly aware of your surroundings while still paralyzed. Surprisingly, sleep paralysis is quite common (about 25-40% of people report experiencing it) and, although incidence seems to vary across cultures, it’s found worldwide (Cheyne, Rueffer, & Newby-Clark, 1999). Importantly, sleep paralysis is not always accompanied by hallucinations, about 30% of respondents in one survey said they had experienced sleep paralysis without hallucinations. Indeed, I’ve experienced sleep paralysis (sans hallucinations) probably half a dozen times or so and was never bothered by them much. (On one occasion I got rather frustrated though – I was awake and kept trying and trying to move but couldn’t. In retrospect, I’m a bit perplexed why it didn’t bother me more).
Around 3 a.m. on November 23rd, I woke up and heard my sister Liana’s voice. At first I thought I was back in Chester House in Cape Town (where I lived with Liana for ~ 2 years, in a bachelor’s flat) but then the voice started angrily lecturing me and telling me details of the dream I just had. (Probably due to sleep inertia, I don't now remember what I dreamt, but I distinctly recall the voice referring to minute details of my dream). This went on for about 5 minutes and as I slowly became aware of where I was - about 1,500km away from where Liana lives - I realized the voice was disembodied and became more and more frightened. I must emphasize, in fact, that the word “frightening” doesn’t come near to doing justice to the feeling. It was numbingly scary, petrifying, bloodcurdlingly terrifying.
And this, remember, was my sister’s voice — not something I’m scared of under normal conditions. Other people who have these hallucinations report not only hearing things, but experience visual, tactile and proprioceptive hallucinations. They report seeing old hags, demons, aliens, ghosts or other malevolent beings or report experiencing floating or falling sensations and so on. The fact that I just heard my sister's voice makes me suspect I had a fairly mild hallucination; I can only imagine how much more frightening it must be to see, say, an alien next to your bed while you're supine and paralyzed.
That brings me to my subtitle: "How I Learnt to Stop Belittling True Believers and Love Skepticism". For me, having this experience has really driven home the argument, made most forcefully by Carl Sagan and Joe Nickell, that it's a false dichotomy to think people who have paranormal experiences are either lying or crazy. There's a third alternative: they're having genuine experiences but then interpret the experiences incorrectly. That is, people really do experience what looks for all the world like an alien standing over their bed — but it's not really an alien, it's a phantom in the brain. And that's why I've learnt to love skepticism (even more): as soon as I woke up and got over my sleep inertia, I realized what had happened and was no longer afraid. My sister was due to give birth, so she was in my thoughts; I knew what sleep paralysis was, having experienced it before, and I knew about hypnopompic and hypnogogic hallucinations from The Skeptics Guide to the Universe podcast. (Thanks guys). So as soon as I thought about it clearly, I knew what had happened, could place my experience in perspective and I was thus saved from further negative emotions and a silly ontology.
My experience also made me realize just how compelling seemingly paranormal experiences can be. It's completely understandable that someone who regularly has hypnogogic hallucinations, lacks training in skeptical or critical thinking, knows nothing about neuroscience, and who is immersed in a popular culture full of references to paranormal entities will interpret such experiences as genuinely paranormal events. Belittling the experiences of the true believers in the paranormal, I now believe, is not appropriate — they deserve our sympathy, not our ridicule.
Links
- Sleep paralysis accounts.
- Skepdic on sleep paralysis.
- Chris Mooney, "Waking up to sleep paralysis", Doubt & About blog.
- Joe Nickell, "A Study of Fantasy Proneness in the Thirteen Cases of Alleged Encounters in John Mack's Abduction", The Skeptical Inquirer.
- Susan Blackmore, "Abduction by Aliens or Sleep Paralysis?", The Skeptical Inquirer.
- Robert Novella, "Hypnogogia: An Explanation for Strange Nighttime Visitations", The Connecticut Skeptic.
Cheyne, J. A., Rueffer, S. D., and Newby-Clark, I. R. (1999) “Hypnagogic and Hypnopompic Hallucinations during Sleep Paralysis: Neurological and Cultural Construction of the Night-Mare,” Consciousness and Cognition, 8: 319–337
Thursday, November 29, 2007
Follow-up: Active Parents Raise Active Children
Alas, I was right in my condemnation of Mattocks et. al.'s study into the causes of children's degree of physical activity: genetics was not controlled for at all and, in fact, no attempt was made to do so. Shorty after writing my blog entry on the study, I emailed the lead author, Culum Mattocks, pointing out that genetics was a possible confound and asking him whether I somehow missed how they controlled for it. He replied:
A couple of other brief observations. Firstly, one most certainly does not "need analysis of DNA samples" to control for genetics, as Mattocks suggests in his email. (Besides, that seems to be already available). My colleague (and supervisor) David Spurrett summed up the reason rather aptly: "you don't need DNA samples to tell how related children are to their parents." What you would need to control for genetics in such a study is some sort of intervention (asking parents to be more active than they normally would be around their young children) or a twin study.Secondly, and finally, one may wonder how Mattocks et. al.'s paper got past peer review and onto the pages of the BMJ in the first place. Perhaps the fact that BMJ published this study sheds some light on the matter.
Thanks for your interest in our article. We were unable to control for genetic factors in this study. We do intend to look at genetic influences on physical activity in the future in our study but were not able to do so at this time as that will need analysis of DNA samples.This, frankly, is simply not good enough. As I pointed out to Mattocks in reply, the point of science is to understand the causes of observed phenomena - and we come to such an understanding by subjecting our causal hypotheses about what's going on to empirical tests that can distinguish between alternative theses. In its current form, their study tells us, basically, "active parents raise active children OR active parents have active children OR some combination of the two OR some other factors are at play". It tells us, in short, nothing we didn't know before Mattocks and his co-authors spent their large grant on fancy accelerometers and other paraphernalia. This is absolutely criminal in my opinion: Mattocks et. al. squandered valuable scientific resources, took up the time of the Avon cohort, missed an opportunity to find out something of value about an important topic, misled the public and, worse of all, engaged in bad science and sloppy thinking. At least BMJ published my "rapid response" to the paper on their website (basically a precis of my blog entry) , it can be found here: "A possible confound: genetics - Michael Meadon".
A couple of other brief observations. Firstly, one most certainly does not "need analysis of DNA samples" to control for genetics, as Mattocks suggests in his email. (Besides, that seems to be already available). My colleague (and supervisor) David Spurrett summed up the reason rather aptly: "you don't need DNA samples to tell how related children are to their parents." What you would need to control for genetics in such a study is some sort of intervention (asking parents to be more active than they normally would be around their young children) or a twin study.
Wednesday, November 28, 2007
Your brain on politics: the bad and the better
The bad
Amodio et. al. conducted this test by using an electroencephalogram to record the ACC activity in 43 subjects who were asked to complete a go/no-go association task (Nosek & Banaji, 2001). For the task, participants were placed in a sound-proof room, in front of a computer screen in the center of which either an "M" or a "W" appeared. Half the subjects were instructed to "go" (i.e. hit a key) when they saw an "M" and do nothing ("no-go") when they saw a "W", while the other half were asked to do the opposite. The task consisted of 500 trails, 80% of which consisted of the "go" stimulus and 20% of the "no-go" stimulus. This meant that for half the subjects "M" became a habitual response (which needed to be inhibited when they saw a "W") and for the other half "W" became habitual (which needed to be inhibited when they saw an "M"). Additionally, before the task was administered, subjects reported their political attitudes confidentially on a scale ranging from -5 (very liberal) to +5 (very conservative).
The results were very suggestive. Firstly, however, it is important to note that there are in fact two types of finding in this study: the behavioral findings (which the authors do not focus on) and the cognitive neuroscience findings (which the authors emphasized and most of the subsequent discussion revolved around). The behavioral finding - which is interesting all by itself - is that liberals were more accurate than conservatives on the no-go trails (r(41) = 0.30, P less than 0.05) which "suggests that a more conservative orientation is related to greater persistence in a habitual response pattern, despite signals that this response pattern should change".
The neurocognitive findings were (among other things) that the response-locked error-related negativity (ERN) - a measure of conflict between a habitual tendency and an alternative - was strongly correlated (r(41) = 0.59, P less than 0.001) with political attitudes:
Additionally, liberalism was strongly associated with greater conflict-related neural activity when a habitual response had to be inhibited:
Subsequently, localization analysis was performed, which confirmed that the above mentioned ERN activity originated from the ACC. Amodio et. al. conclude that "taken together, our results are consistent with the view that political orientation, in part, reflects individual differences in the functioning of a general mechanisms related to cognitive control and self regulation".
A couple of observations. The study is clearly preliminary and a good deal of the reporting of it in the lay press went far beyond the evidence. The authors, however, obviously cannot be blamed for this - they were careful not to stray from the evidence in their paper. Furthermore, only 43 subjects took part in the study and, worse, only 7 of those self-reported as conservative. The findings would have to be replicated by a different team in a different part in the US with a larger number of participants before too much stock can be placed in them. For now this can be filed under "interesting and suggestive but preliminary". We'll have to wait and see how the literature develops.
Links
A disturbingly bad article, entitled "This is Your Brain on Politics", appeared recently in the New York Times. It presented purported "research" about the brains of swing voters in the 2008 US Presidential Elections but, unfortunately, the article does little but illustrate the dangers of circumventing the peer-review process and the shocking state of science journalism in the mainstream media. Luckily, the NYT published an angry letter by a group of cognitive neuroscientists condemning the article and the blogosphere responded forcefully, among the blogs that attacked the piece were: Bad Science, Neurocritic, Mindhacks, Brainethics and Natural Rationality. Subsequently, Nature published an editorial also condemning the article and even Slate joined in.
The better
Thankfully there has also been some better recent research concerning 'the brain on politics' and good media coverage thereof to boot. The subject of last week's edition of ABC Radio National's fantastic radio show/podcast, All in the Mind, was "The Political Brain" and the show discussed, among other things, an interesting study in Nature Neuroscience entitled "Neurocognitive correlates of liberalism and conservatism" (see also the supplementary materials). The study, led by NYU assistant professor of psychology David Amodio, evoked considerable interest and was widely discussed by the science blogging community. (See links below). I suspect the study has been somewhat misunderstood, so, despite it being stale by web standards, I'll look at it in some detail.
The hypothesis the authors defend is that political orientation (conservative vs. liberal) is "associated with individual differences in a basic neurocognitive mechanism involved broadly in self-regulation" (Amodio et. al., 2007: 1246). They go about testing this proposition in a somewhat tortuous way: previous research had shown that conservatives are "more structured and persistent in their judgments and approaches to decision-making" whereas liberals "report higher tolerance of ambiguity and complexity, and greater openness to new experiences". Other research showed that psychological differences between liberals and conservatives "map onto the... self-regulatory process of conflict monitoring" (the system that detects a mismatch between habitual responses and the response required in the current situation) which in turn has been "associated with neurocognitive activity in the anterior cingulate cortext"(ACC). So, to test whether liberals and conservatives differ in their patterns of self-regulation, the authors measured the acitivity of the ACC in a situation requiring conflict-monitoring.
The better
Thankfully there has also been some better recent research concerning 'the brain on politics' and good media coverage thereof to boot. The subject of last week's edition of ABC Radio National's fantastic radio show/podcast, All in the Mind, was "The Political Brain" and the show discussed, among other things, an interesting study in Nature Neuroscience entitled "Neurocognitive correlates of liberalism and conservatism" (see also the supplementary materials). The study, led by NYU assistant professor of psychology David Amodio, evoked considerable interest and was widely discussed by the science blogging community. (See links below). I suspect the study has been somewhat misunderstood, so, despite it being stale by web standards, I'll look at it in some detail.The hypothesis the authors defend is that political orientation (conservative vs. liberal) is "associated with individual differences in a basic neurocognitive mechanism involved broadly in self-regulation" (Amodio et. al., 2007: 1246). They go about testing this proposition in a somewhat tortuous way: previous research had shown that conservatives are "more structured and persistent in their judgments and approaches to decision-making" whereas liberals "report higher tolerance of ambiguity and complexity, and greater openness to new experiences". Other research showed that psychological differences between liberals and conservatives "map onto the... self-regulatory process of conflict monitoring" (the system that detects a mismatch between habitual responses and the response required in the current situation) which in turn has been "associated with neurocognitive activity in the anterior cingulate cortext"(ACC). So, to test whether liberals and conservatives differ in their patterns of self-regulation, the authors measured the acitivity of the ACC in a situation requiring conflict-monitoring.
Amodio et. al. conducted this test by using an electroencephalogram to record the ACC activity in 43 subjects who were asked to complete a go/no-go association task (Nosek & Banaji, 2001). For the task, participants were placed in a sound-proof room, in front of a computer screen in the center of which either an "M" or a "W" appeared. Half the subjects were instructed to "go" (i.e. hit a key) when they saw an "M" and do nothing ("no-go") when they saw a "W", while the other half were asked to do the opposite. The task consisted of 500 trails, 80% of which consisted of the "go" stimulus and 20% of the "no-go" stimulus. This meant that for half the subjects "M" became a habitual response (which needed to be inhibited when they saw a "W") and for the other half "W" became habitual (which needed to be inhibited when they saw an "M"). Additionally, before the task was administered, subjects reported their political attitudes confidentially on a scale ranging from -5 (very liberal) to +5 (very conservative).
The results were very suggestive. Firstly, however, it is important to note that there are in fact two types of finding in this study: the behavioral findings (which the authors do not focus on) and the cognitive neuroscience findings (which the authors emphasized and most of the subsequent discussion revolved around). The behavioral finding - which is interesting all by itself - is that liberals were more accurate than conservatives on the no-go trails (r(41) = 0.30, P less than 0.05) which "suggests that a more conservative orientation is related to greater persistence in a habitual response pattern, despite signals that this response pattern should change".
The neurocognitive findings were (among other things) that the response-locked error-related negativity (ERN) - a measure of conflict between a habitual tendency and an alternative - was strongly correlated (r(41) = 0.59, P less than 0.001) with political attitudes:
Additionally, liberalism was strongly associated with greater conflict-related neural activity when a habitual response had to be inhibited:
Subsequently, localization analysis was performed, which confirmed that the above mentioned ERN activity originated from the ACC. Amodio et. al. conclude that "taken together, our results are consistent with the view that political orientation, in part, reflects individual differences in the functioning of a general mechanisms related to cognitive control and self regulation".A couple of observations. The study is clearly preliminary and a good deal of the reporting of it in the lay press went far beyond the evidence. The authors, however, obviously cannot be blamed for this - they were careful not to stray from the evidence in their paper. Furthermore, only 43 subjects took part in the study and, worse, only 7 of those self-reported as conservative. The findings would have to be replicated by a different team in a different part in the US with a larger number of participants before too much stock can be placed in them. For now this can be filed under "interesting and suggestive but preliminary". We'll have to wait and see how the literature develops.
Links
- Coverage of the Amodio paper on other blogs: NeuroLogica, Cognitive Daily, Natural Rationality, Crooked Timber, Mixing Memory, and Neurocritic.
- News coverage: Scientific American.
Bibliography
Amodio, D.A., Jost, J.T., Master, S.L., Yee, C.M. (2007). Neurocognitive correlates of liberalism and conservatism. Nature Neuroscience, 10, 1246-1247. DOI: 10.1038/nn1979
Nosek, B. A., & Banaji, M. R. (2001) "The go/no-go association task," Social Cognition, 19(6): 161-176.
Amodio, D.A., Jost, J.T., Master, S.L., Yee, C.M. (2007). Neurocognitive correlates of liberalism and conservatism. Nature Neuroscience, 10, 1246-1247. DOI: 10.1038/nn1979
Nosek, B. A., & Banaji, M. R. (2001) "The go/no-go association task," Social Cognition, 19(6): 161-176.
Tuesday, November 27, 2007
Video: The Stanford prison experiment
One of my favorite quotes in social psychology is from Stanley Milgram's seminal Obedience to Authority (1974): "The social psychology of this century reveals a major lesson: often it is not so much the kind of person a man is as the kind of situation in which he finds himself that determines how he will act." Two classic experiments illustrate this view perfectly: Milgram's own obedience studies and Philip Zimbardo's Stanford prison experiment. The following video contains (inter alia) extremely interesting - and poignant - reflections on this view by an ex-guard and an ex-prisoner in Zimbardo's experiment. (Click here to go directly to the video).
Links
Milgram, S. (1974) Obedience to Authority (New York: Harper & Row).
Links
- Official website of the Stanford Prison Experiment
- Zimbardo interviewed on All in the Mind
- Psyblog's excellent entry on the Milgram obedience studies
Milgram, S. (1974) Obedience to Authority (New York: Harper & Row).
Blogging about peer-reviewed research
Some of you might have noticed that in my post about the recent BMJ article about active parents raising active children I started using BPR3's icons indicating which of my posts are about peer-reviewed research. The icons (which can be seen here) are designed to draw attention to thoughtful, serious blog posts on papers that have been published in journals reviewed by relevant experts. (See BPR3's guideline for more information). An upcoming feature - which I hope to participate in soon - will aggregate all blog posts using the icons at a central location on the BPR3 website, which in turn will draw more attention to quality science blogs. (Something I sure hope this blog counts as a token of...).
Video: Richard Wiseman
Richard Wiseman, the holder of the world's only professorship in the public understanding of psychology, is this week's guest on CFI's fantastic podcast Point of Inquiry. He has produced some seriously cool videos demonstrating various psychological effects, several of which have gone viral on YouTube. I've selected my two favorites and embedded them below, there's a full listing of available videos on Wiseman's YouTube channel.
The first video, embedded below (or click here to go directly to the video at YouTube), is called "colour changing card trick" and is stupendously good. I don't want to spoil it for you by giving too much away, but you'll feel blind afterwards - I certainly did!
The second video, also embedded below (or click here to go directly to the video at YouTube), is called "The Prediction" and is equally fantastic - it would have freaked me out if I still believed in free-will.
The first video, embedded below (or click here to go directly to the video at YouTube), is called "colour changing card trick" and is stupendously good. I don't want to spoil it for you by giving too much away, but you'll feel blind afterwards - I certainly did!
The second video, also embedded below (or click here to go directly to the video at YouTube), is called "The Prediction" and is equally fantastic - it would have freaked me out if I still believed in free-will.
Monday, November 26, 2007
Peer-reviewed nonsense: Active Parents Raise Active Children
The British Medical Journal - which is highly respected and has the 6th highest impact factor of all general medical journals - has just published an almost entirely worthless study on the effect of parental physical activity on the physical activity of their 11-12 year old children (Mattocks et. al., 2007). The study is worthless, in short, because it proceeds as if the entire field of behavioral genetics does not exist; the authors simply assume their conclusions are not confounded by genetic factors. It astonishes me that such fatally flawed article can get past peer-review in such a prestigious journal. That such an obvious confound as genetics can be overlooked is a testament to the continuing detrimental effect of the blank slate on modern science (Pinker, 2002).
First a bit more about the study itself. The authors used data from the Avon longitudinal study of parents and children, which collected (and is continuing to collect) a wealth of data from 14,061 families. The specific question addressed was which factors in the child's early life (defined as before age 5) influenced the objectively measured physical activity of the same children at ages 11-12. The authors collected the physical activity data with uniaxial actigraph accelerometers from 5,451 11-12 year old children in the Avon cohort and then looked at data collected when the children were aged 5 or younger for causal variables. In other words, the researchers wanted to know which early life variables predicted physical activity at age 11-12. The conclusion of the research was:
A slight problem...
Children share 50% of their genes with each parent, and since all human behavioral traits are heritable (the so-called First Law of Behavioral Genetics, Turkheimer, 2000), genetic factors are always possible confounds when relating parenting style (or other parental behavior) to outcomes in the children. As Turkheimer explains:
To be clear, I'm not claiming children are not socialized in this way; my point is we cannot tell one way or the other from the data presented because it fails to distinguish between the relevant causal hypotheses. I really hope I've somehow been daft by missing how the authors controlled for genetic factors. The alternative is that a leading medical journal published an article that is scientifically illiterate, that overlooks obvious possible confounds and that is thus worthless in terms of deciding what causes 11-12 year old children's degree of physical acitivity. Frankly, that I've made a mistake is far more palatable to me.
(See also: ScienceDaily's report on this research).
----------------
Mattocks, C., Ness, A., Deere, K., Tilling, K., Leary, S., Blair, S., & Riddoch, C. (2008). Early life determinants of physical activity in 11 to 12 year olds: cohort study BMJ, 336 (7634), 26-29 DOI: 10.1136/bmj.39385.443565.BE
Turkheimer, E. (2000) "Three Laws of Behavior Genetics and What They Mean," Current Directions in Psychological Science, 9(5): 160-164.
Pinker, S. (2002) The Blank Slate: The Modern Denial of Human Nature (London: Penguin).
First a bit more about the study itself. The authors used data from the Avon longitudinal study of parents and children, which collected (and is continuing to collect) a wealth of data from 14,061 families. The specific question addressed was which factors in the child's early life (defined as before age 5) influenced the objectively measured physical activity of the same children at ages 11-12. The authors collected the physical activity data with uniaxial actigraph accelerometers from 5,451 11-12 year old children in the Avon cohort and then looked at data collected when the children were aged 5 or younger for causal variables. In other words, the researchers wanted to know which early life variables predicted physical activity at age 11-12. The conclusion of the research was:
We have shown that children are slightly more active if their parents are active early in the child’s life. This suggests that encouraging physical activity in parents may also influence their children to become more active, with the added advantage that physically active parents are healthier (Mattocks et. al., 2007: 7).So, in other words, active parents socialize their children to be active themselves. (It's clear the authors are thinking in terms of socialization, something the following quotation perhaps illustrates a bit better: "in our study, maternal activity during pregnancy... was positively associated with physical activity in the children. It is unlikely that this is due to biological factors in utero but is more likely that physical activity during pregnancy is a marker for later maternal physical activity and that this in turn influences children’s physical activity" [Mattocks et. al., 2007: 6].)
A slight problem...
Children share 50% of their genes with each parent, and since all human behavioral traits are heritable (the so-called First Law of Behavioral Genetics, Turkheimer, 2000), genetic factors are always possible confounds when relating parenting style (or other parental behavior) to outcomes in the children. As Turkheimer explains:
It is no longer possible to interpret correlations among biologically related family members as prima facie evidence of sociocultral causal mechanisms. If the children of depressed mothers grow up to be depressed themselves, it does not necessarily demonstrate that being raised by a depressed mother is itself depressing. The children might have grown up equally depressed if they had been adopted and raised by different mothers, under the influence of their biological mother's genes (2000: 162).The exact same problem holds for the Mattocks study: one can't simply assume parental physical activity (or lack thereof) influences children to be active (or inactive) because it's possible that sedentary children inherit sedentary genes from their sedentary parents and active children inherit active genes from their active parents. Or, to put it differently, the fact that the physical activity of parents when the children were young is correlated with the children's degree of activeness later on simply does not constitute evidence of a socialization effect.
To be clear, I'm not claiming children are not socialized in this way; my point is we cannot tell one way or the other from the data presented because it fails to distinguish between the relevant causal hypotheses. I really hope I've somehow been daft by missing how the authors controlled for genetic factors. The alternative is that a leading medical journal published an article that is scientifically illiterate, that overlooks obvious possible confounds and that is thus worthless in terms of deciding what causes 11-12 year old children's degree of physical acitivity. Frankly, that I've made a mistake is far more palatable to me.
(See also: ScienceDaily's report on this research).
----------------
Mattocks, C., Ness, A., Deere, K., Tilling, K., Leary, S., Blair, S., & Riddoch, C. (2008). Early life determinants of physical activity in 11 to 12 year olds: cohort study BMJ, 336 (7634), 26-29 DOI: 10.1136/bmj.39385.443565.BE
Turkheimer, E. (2000) "Three Laws of Behavior Genetics and What They Mean," Current Directions in Psychological Science, 9(5): 160-164.
Pinker, S. (2002) The Blank Slate: The Modern Denial of Human Nature (London: Penguin).
Sunday, November 25, 2007
Video: The Amazing Bonobo
Primatologist Susan Savage-Rumbaugh has an immensely interesting TEDTalk in which she disputes the view that animal behavior is "hardwired". She shows videos of her research on bonobos - including the apes playing a computer game, making crude stone tools and following verbal instructions to light and douse a fire. The bonobos evince quite a few behaviors that are very surprising to the uninitiated. (as I can attest...).
In any case, the video is embedded below. Alternatively, click here to go directly to the video at the TED website.
In any case, the video is embedded below. Alternatively, click here to go directly to the video at the TED website.
Interesting research, in brief
Occasionally I will summarize (but not analyze) a handful of attention-grabbing recent research findings and link to the original papers so interested readers can follow up for themselves. Sometimes I might go on to write a more thorough analysis of particular papers mentioned in my “in brief” posts.Animals...
The first study that caught my eye was that, apparently, elephants stereotype. I'm editorializing, of course, but according to research published in Current Biology, elephants distinguish between different human ethnic groups. In the Amboseli Reserve, in Kenya, elephants sometimes encounter Maasai men who attempt to prove their virility by spearing them. The Kamba ethnic group, on the other hand, are apparently generally nice to the elephants and let them be. As a result, "Elephants showed greater fear when they detected the scent of garments previously worn by Maasai than by Kamba men, and they reacted aggressively to the color associated with Maasai. Elephants are therefore able to classify members of a single species into subgroups that pose different degrees of danger."
The second interesting recent animal study tested a counter-argument to the hypothesis that chimpanzees have culture (or engage in differential "social learning"). Observed behavioral differences between non-interacting chimp troops, so this counter-argument runs, could be due to genetic differences between the groups and therefore may not be attributed to cultural variation. The study, published in PNAS, conducted a cladistic analysis comparing the phylogeny and behavior of different groups. The conclusion? "These findings are inconsistent with the hypothesis that patterns of behavioral differences at the population level are genetically determined. Instead, they are in line with a growing number of studies involving captive groups and wild populations that suggest many chimpanzee behaviors are socially learned and can be considered cultural."
Children...
Far from corrupting the youth, philosophy may in fact be good for children. Research published in Educational Psychology suggests that lessons consisting of a Socratic dialogue between students and a teacher has long term cognitive benefits. This finding is a follow-up on the same authors' earlier study which found 16 months of weekly 1 hour philosophy lessons "showed significant standardized gains in verbal and also in non-verbal and quantitative aspects of reasoning" whereas controls showed no gains. Two years later, the researchers tracked down 96 experimental and 52 control subjects and re-administered the cognitive performance tests. They found that "the significant pre-post cognitive ability gains in the experimental group in primary school were maintained towards the end of their second year of secondary school" whereas "the control group showed an insignificant but persistent deterioration in scores from pre- to post-test to follow-up." As far as I am aware, only the International Baccalaureate curriculum incorporates philosophical training at school-level (and then not early enough). Given these findings, that's quite a shame. (See also BPS Research Digest's report on this research).
In possibly the most interesting study I've seen for a while, Bruce Ellis and Marilyn Essex test a life history model of menarche. In an influential 1991 paper, "Childhood experience, interpersonal development, and reproductive strategy," Belsky, Steinberg and Draper proposed the psychosocial acceleration theory which holds (among other things) that girls adaptively adjust their onset of puberty based on the quality of paternal investment and other factors reflecting their living conditions. Ellis and Essex set out to test this theory comprehensively by following 570 pregnant women and their partners longitudinally and determing the effect of socio-economic status, marital conflict, parental mental illness, parental investment (inter alia) on the age of menarche in their children. Their conclusion is that the "quality of parental investment... is the most important mechanism through which young children receive information about levels of stress and support in their local environments, and that this information provides a basis for adaptively adjusting pubertal timing." (See also ScienceDaily's report on this research).
Infants...
It has been known for some time that "emotion drives attention"; that biologically significant stimuli (snakes and spiders being the classic examples) capture the attention of animals (including humans) much quicker than non-biologically significant stimuli. The focus of this literature, however, has been primarily on threatening biological stimuli; a category arguably much narrower than biologically significant stimuli. Now Tobias Brosch, David Sander, and Klaus Scherer argue in their new study that humans also pay preferential attention to newborn infants. The authors suggest, furthermore, that their "results support the notion that a common evaluative process may be responsible for the emotional modulation of selective attention to both negative and positive affectively arousing stimuli."
According to research just released in Nature, infants as young as 6 months have such a well developed theory of mind that they take individuals' behavior towards others into account when forming preferences. Using a methodology involving an innovative puppet show, the authors show that "infants prefer an individual who helps another to one who hinders another, prefer a helping individual to a neutral individual, and prefer a neutral individual to a hindering individual" and conclude their finding "supports the view that social evaluation is a biological adaptation." (See also Nature News's article on this research).
The first study that caught my eye was that, apparently, elephants stereotype. I'm editorializing, of course, but according to research published in Current Biology, elephants distinguish between different human ethnic groups. In the Amboseli Reserve, in Kenya, elephants sometimes encounter Maasai men who attempt to prove their virility by spearing them. The Kamba ethnic group, on the other hand, are apparently generally nice to the elephants and let them be. As a result, "Elephants showed greater fear when they detected the scent of garments previously worn by Maasai than by Kamba men, and they reacted aggressively to the color associated with Maasai. Elephants are therefore able to classify members of a single species into subgroups that pose different degrees of danger."
The second interesting recent animal study tested a counter-argument to the hypothesis that chimpanzees have culture (or engage in differential "social learning"). Observed behavioral differences between non-interacting chimp troops, so this counter-argument runs, could be due to genetic differences between the groups and therefore may not be attributed to cultural variation. The study, published in PNAS, conducted a cladistic analysis comparing the phylogeny and behavior of different groups. The conclusion? "These findings are inconsistent with the hypothesis that patterns of behavioral differences at the population level are genetically determined. Instead, they are in line with a growing number of studies involving captive groups and wild populations that suggest many chimpanzee behaviors are socially learned and can be considered cultural."
Children...
Far from corrupting the youth, philosophy may in fact be good for children. Research published in Educational Psychology suggests that lessons consisting of a Socratic dialogue between students and a teacher has long term cognitive benefits. This finding is a follow-up on the same authors' earlier study which found 16 months of weekly 1 hour philosophy lessons "showed significant standardized gains in verbal and also in non-verbal and quantitative aspects of reasoning" whereas controls showed no gains. Two years later, the researchers tracked down 96 experimental and 52 control subjects and re-administered the cognitive performance tests. They found that "the significant pre-post cognitive ability gains in the experimental group in primary school were maintained towards the end of their second year of secondary school" whereas "the control group showed an insignificant but persistent deterioration in scores from pre- to post-test to follow-up." As far as I am aware, only the International Baccalaureate curriculum incorporates philosophical training at school-level (and then not early enough). Given these findings, that's quite a shame. (See also BPS Research Digest's report on this research).
In possibly the most interesting study I've seen for a while, Bruce Ellis and Marilyn Essex test a life history model of menarche. In an influential 1991 paper, "Childhood experience, interpersonal development, and reproductive strategy," Belsky, Steinberg and Draper proposed the psychosocial acceleration theory which holds (among other things) that girls adaptively adjust their onset of puberty based on the quality of paternal investment and other factors reflecting their living conditions. Ellis and Essex set out to test this theory comprehensively by following 570 pregnant women and their partners longitudinally and determing the effect of socio-economic status, marital conflict, parental mental illness, parental investment (inter alia) on the age of menarche in their children. Their conclusion is that the "quality of parental investment... is the most important mechanism through which young children receive information about levels of stress and support in their local environments, and that this information provides a basis for adaptively adjusting pubertal timing." (See also ScienceDaily's report on this research).
Infants...
It has been known for some time that "emotion drives attention"; that biologically significant stimuli (snakes and spiders being the classic examples) capture the attention of animals (including humans) much quicker than non-biologically significant stimuli. The focus of this literature, however, has been primarily on threatening biological stimuli; a category arguably much narrower than biologically significant stimuli. Now Tobias Brosch, David Sander, and Klaus Scherer argue in their new study that humans also pay preferential attention to newborn infants. The authors suggest, furthermore, that their "results support the notion that a common evaluative process may be responsible for the emotional modulation of selective attention to both negative and positive affectively arousing stimuli."
According to research just released in Nature, infants as young as 6 months have such a well developed theory of mind that they take individuals' behavior towards others into account when forming preferences. Using a methodology involving an innovative puppet show, the authors show that "infants prefer an individual who helps another to one who hinders another, prefer a helping individual to a neutral individual, and prefer a neutral individual to a hindering individual" and conclude their finding "supports the view that social evaluation is a biological adaptation." (See also Nature News's article on this research).
Tuesday, November 20, 2007
Evolutionary psychology as an “extraordinary claim”
Channeling David Hume, Carl Sagan famously said, "extraordinary claims require extraordinary evidence". As Richard Dawkins notes in the Afterword to Buss (2005), evolutionary psychology [EP], oddly, is often thought to make extraordinary claims meriting strong skepticism. Now, clearly, to accept the proposition that telepathic communication is occurring in a particular case, we would require extraordinary evidence and "demand multiple replications under ultrarigorous, double-blind controlled conditions, with a battery of professional illusionists as skeptical scrutineers and with a statistical p-value less than one in a billion" (2005: 977). On the other hand, the claim that, say, two people can communicate via a telephone or by exchanging letters would elicit practically no skepticism. In between these extremes are claims that one ought to be somewhat skeptical about and require a good deal (but not an extraordinary amount) of evidence before they can be accepted provisionally. Examples of this class include the proposition that smoking causes cancer (when it was first posited) and the claim that, say, cocaine has epigenetic effects on the hippocampus. The difference between the cases, it would seem, has to do with a priori plausibility: the extent to which the proposition under consideration fits in with everything else we know about the world. So where on this spectrum does evolutionary psychology fall?
Dawkins makes a convincing case that many critics of EP incorrectly place it on the telepathy end of the spectrum when it belongs in the middle, much nearer to the plausible end. Evolutionary psychology, notes Dawkins, "amounts to the exceedingly modest assertion that minds are on the same footing as bodies where Darwinian natural selection is concerned" (2005: 978). Indeed, it is the opposite conclusion – that human psychology is exempt from the forces that govern the rest of the natural world – that requires extraordinary evidence. It is the proposition that humans are unique, and somehow not continuous with the natural world, that is a priori implausible given everything else we know. Dawkins makes the same argument with respect to modularity: since "modularity is a universally good design principle which pervades engineering, software, and biology" and since it "is such an obvious way to run any complex operation, we should positively expect that the mind would be modularized" (2005: 978, emphasis added). The controversy over modularity of mind is therefore often so heated because its opponents are far more skeptical of it than they ought to be.
While I think Dawkins is exactly right when it comes to the many of EP’s critics, it is only fair to note that there is a group of people who don’t make the mistakes he discusses. Some cognitive scientists and cognitive psychologist accept the mind is a product of the brain and agree the brain evolved by natural selection, but then deny an evolutionary perspective is illuminating. (see this blog post). While we should expect an evolutionary perspective to offer insights, it is possible to adopt a functionalist perspective (a "design stance" in Dennett’s parlance) without being explicitly evolutionary. (Indeed, a good deal was discovered about human physiology using this method long before the publication of Darwin’s theory). Nonetheless, it is still clear that this sub-class of EP's critics ought to locate particular EP propositions – say, that female mate preference varies with menstruation cycle – in the middle of the skepticism spectrum, not at the telepathy end. Sometimes it seems that even these critics – such as the blog entry liked above – fail to do so and I can't help but detect antipathy bordering on bias.
Bibliography
Dawkins, R. (2005) “Afterword,” in Buss, M. (ed.) Handbook of Evolutionary Psychology (Hoboken, NJ: John Wiley & Sons)
Dawkins makes a convincing case that many critics of EP incorrectly place it on the telepathy end of the spectrum when it belongs in the middle, much nearer to the plausible end. Evolutionary psychology, notes Dawkins, "amounts to the exceedingly modest assertion that minds are on the same footing as bodies where Darwinian natural selection is concerned" (2005: 978). Indeed, it is the opposite conclusion – that human psychology is exempt from the forces that govern the rest of the natural world – that requires extraordinary evidence. It is the proposition that humans are unique, and somehow not continuous with the natural world, that is a priori implausible given everything else we know. Dawkins makes the same argument with respect to modularity: since "modularity is a universally good design principle which pervades engineering, software, and biology" and since it "is such an obvious way to run any complex operation, we should positively expect that the mind would be modularized" (2005: 978, emphasis added). The controversy over modularity of mind is therefore often so heated because its opponents are far more skeptical of it than they ought to be.
While I think Dawkins is exactly right when it comes to the many of EP’s critics, it is only fair to note that there is a group of people who don’t make the mistakes he discusses. Some cognitive scientists and cognitive psychologist accept the mind is a product of the brain and agree the brain evolved by natural selection, but then deny an evolutionary perspective is illuminating. (see this blog post). While we should expect an evolutionary perspective to offer insights, it is possible to adopt a functionalist perspective (a "design stance" in Dennett’s parlance) without being explicitly evolutionary. (Indeed, a good deal was discovered about human physiology using this method long before the publication of Darwin’s theory). Nonetheless, it is still clear that this sub-class of EP's critics ought to locate particular EP propositions – say, that female mate preference varies with menstruation cycle – in the middle of the skepticism spectrum, not at the telepathy end. Sometimes it seems that even these critics – such as the blog entry liked above – fail to do so and I can't help but detect antipathy bordering on bias.
Bibliography
Dawkins, R. (2005) “Afterword,” in Buss, M. (ed.) Handbook of Evolutionary Psychology (Hoboken, NJ: John Wiley & Sons)
Wednesday, November 14, 2007
Video: Pinker on violence
Harvard evolutionary psychologist Steven Pinker argues in his fantastic recent TEDTalk that "everything you know [about violence] is wrong". Pinker recapitulates the argument he made in The Blank Slate that human beings today are far less violent that they have ever been - that, to put it crudely, Hobbes was right and Locke was wrong. The video, embedded below, is well worth watching... Alternatively, click here to go directly to the video at the TED website.
Saturday, November 3, 2007
Welcome…
So this is my blog – it will consist almost entirely of my irregular musing and reflections on recent (and sometimes not so recent) published academic papers in evolutionary and social psychology. Occasionally I might indulge myself by venturing further afield, probably mainly into political science. I may even sometimes fail to take myself seriously and blog about something other than a specific academic paper…
Such, I believe, is the source of the Ionian Enchantment. Preferring a search for objective reality over revelation is another way of satisfying religious hunger. It is an endeavor almost as old as civilization and intertwined with traditional religion, but it follows a very different course – a stoic’s creed, an acquired taste, a guidebook to adventure plotted across rough terrain. It aims to save the spirit, not by surrender but by liberation of the human mind. Its central tenet, as Einstein knew, is the unification of knowledge. When we have unified enough certain knowledge, we will understand who we are and why we are here. (1998: 7)
References
Wilson, E. O. (1998) Consilience: The Unity of Knowledge (
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