10 Problems with Memetics

As I have mentioned before, I have never been a fan of memetics: it always struck me as a potentially interesting redescription, but not as a genuine causal theory of culture. I don't think I hate it as much as Greg from Neuroanthropology, though. He thinks memetics "is nonsense on stilts on skates on thin ice on borrowed time (apologies to Bentham), as deserving of the designation ’science’ as astrology, phrenology, or economic forecasting." And he has 10 reasons (including one drawn from yours truly) to back up his position: check out his article.

I do think Greg takes it a bit too far occasionally. Poisoning the well with respect to Susan Blackmore isn't fair and I don't think she's as bad as Greg lets on (when she's not waffling about memetics). She came across as perfectly sensible when she was interviewed on Point of Inquiry, for example. That said, memetics deserves all the flak it gets.

(Hat tip: Simon Halliday)

Astonishing intellectual dishonesty

I have been reading an excellent collection of Stephen Jay Gould's writings off-and-on for while now and have been thoroughly enjoying it. The book is called The Richness of Life: The Essential Stephen Jay Gould and is edited by Steven Rose and Paul McGarr. While Gould is not popular among evolutionary psychologists (and understandably so), I don't want to focus on that right now, because the editors are guilty of truly astonishing intellectual dishonesty. In their introduction to the section of the book about "Sociobiology and Evolutionary Psychology", Rose and McGarr write:

Steve [Gould] was one of those centrally involved in the counterattack on the Wilsonian theses, notably the assumption that central features of United States society - its class, race, and gender structure, its inequalities of status and wealth - were adaptive, evolved feature of the human condition, deducible from Darwinian principles.

They are referring, of course, to E. O. Wilson's seminal 1975 book, Sociobiology: The New Synthesis. The risible thing is, Wilson never said anything even remotely like this. You will look in vain for any statement in the last chapter of Sociobiology or the whole of On Human Nature for an argument (or "assumption") that racism, sexism and inequality are somehow "adaptive". Indeed, given that racism and sexism have certainly waned in the US since 1975, surely the editors are now committed to the position that Wilson thinks current US society is maladapted because of these changes? If so, Wilson is not letting on.

Rose and McGarr again demonstrate there is a strong negative correlation between honesty and Marxism, and a strong positive correlation between Marxism and dumb beliefs.

Xenophobia and dormitive virtues

As most of you will know, South Africa was wracked by despicable and disturbing nation-wide incidents of xenophobic violence over the last couple of months. This has led, correctly, to much public debate about the causes of xenophobia, the conditions under which it results in violence, and what we can do to prevent it. This week’s edition of the Sunday Independent (South Africa’s best weekly), however, contains a near-perfect example of how not to go about explaining this phenomenon. In “Money and narrow nationalism won’t buy us a rainbow” (full article behind paywall), Colleen Lowe Morna asserts:

Xenophobia… has its roots in the failure to accept “otherness” mixed with misguided notions about the superiority of self. That fragile self is constantly threatened by the potential power of the other whether numerical, social, political or economic.

Well, erm, no. A ‘failure to accept otherness’ is not an explanation of xenophobia, it’s simply a redescription of it. Xenophobia, of course, is the hatred or fear of foreigners; the prefix xeno- derives from the Greek xenos meaning stranger or foreigner and the suffix -phobia derives from phobos, or fear. Obviously, strangers are “other”, hatred and prejudice entails one’s own superiority and a non-acceptance of the “other”. Lowe Morna’s purported explanation is, therefore, literally no better than saying opium causes sleep because it has "dormitive virtues".

Arthur Mutambara’s piece in the same newspaper, “Digging up the roots of xenophobia” (paywall again), illustrates another (far less egregious) failure in the debate so far. While Mutambara’s analysis is crudely simplistic, naïve in places and repeatedly factually inaccurate, at least he offers a set of causes that count as a genuine possible explanation. He argues:

At the root of the attacks are the grievances of increased poverty, growing inequality and unemployment, coupled with a deplorable social infrastructure in which health, housing and education are woefully inadequate.

I don’t buy this explanation – it’s clearly causally insufficient and probably doesn’t hold up comparatively – but, as I’ve said, at least it’s a candidate explanation. It is an explanation, however, that focuses exclusively on proximate causes, never mentioning ultimate causes. Why is it that increased poverty, inequality and unemployment where social services are inadequate lead to xenophobic violence? Why doesn't it lead to, oh I don’t know, an irresistible mass urge to recite poetry? Or a sudoku craze? Or anti-albino feeling? We need an account, in other words, of why the social ills Mutambara mentions (or the true proximate causes, whatever they are) lead to xenophobia rather than the infinite number of other possibilities.

In one sense, I admit, the focus on proximate causes is appropriate. There was a time the very same South Africans didn’t commit xenophobic violence (on such a scale, at least), and it’s important to understand what has changed to cause the difference so that we can do something to prevent the violence. But it is possible – perhaps likely – that designing optimum policies to prevent xenophobic violence depends on a full account of the phenomenon, including both proximate and ultimate causes. And evolutionary psychology, of course, has much to say about the ultimate causes of violence and xenophobia.

Kanazawa smackdown

Satoshi Kanazawa is not exactly being welcomed in the science bloggging community. I led the way with a rapid response to his irresponsible call for nuclear genocide, then Cosma Shalizi had a go (as I mentioned yesterday) and now PZ Myers - author of the world's most widely read science blog - roasts Kanazawa as well. I'm sure there will be much more to come...

Kanazawa gets the Cosma treatment

Cosma Shalizi, polymath author of the Three-Toed Sloth blog and keeper of innumerable useful Notebooks, has also responded to Satoshi Kanazawa's crazy call for nuclear genocide. Shalizi concludes Kanazawa is:

the Fenimore Cooper of sociobiology, a man who has leveraged an inability to do data analysis or understand psychometrics into an official blog at Psychology Today, where he gets to advocate genocidal nuclear war as revenge for 9/11. He seems to mean it, rather than be fukayaming.

I plan never to get on Cosma's bad side...

Shermer on the evolutionary psychology of corporate behavior

As I have mentioned before, Michael Shermer has recently become enamored with evolutionary psychology and it’s really showing in his Scientific American columns. He may, however, have become a tad too enthusiastic for his own good. In a recent piece, “Do all companies have to be evil?”, Shermer applies evolutionary psychology to the corporate world. His conclusion, gratifyingly, is that the “greed is good” mindset (Objectivism, for example) not only does not breed success but actually leads to failure. Argues Shermer,

When we apply these evolutionary findings to economic life, we learn that Enron and the Gordon Gekko “Greed Is Good” ethic are the exception and that Google’s “Don’t Be Evil” motto is the rule. Two conditions must be present to accentuate the latter: first, internal trust reinforced by personal relationships, and, second, external rules supported by social institutions.

Shermer then goes on to compare the corporate cultures of Enron and Google in some detail, thereby illustrating his contention about trust and social institutions. This is all very interesting (and certainly worth a read) but I have a few misgivings. What follows are a couple of unconnected observations.

Firstly, Shermer seems to fail to appreciate that to evaluate a hypothesis rigorously it needs to be tested against data not used to come up with it in the first place. That is, if we hypothesize x based on observations y, to test x we need to compare its predictions to a different set of observations z - we can’t use y again because that would be circular. So it makes me worry when Shermer says

By studying how modern companies work, we can gain insights into the evolutionary underpinnings of our morality, including concepts such as reciprocity, altruism and fairness. When we apply these evolutionary findings to economic life…

Is he using human behavior in corporate settings as data for evolutionary psychology or is he using evolutionary psychology to explain human corporate behavior? Perhaps I am being a bit unfair, Shermer has limited space and the above is somewhat tangential, but it remains an important methodological point.

Secondly, it is important to note that in most of the article, Shermer is speculating, not doing science or reporting on established science. For example, he explains Google’s success at creating a productive corporate culture by invoking egalitarianism:

A horizontal corporate structure [like Google’s] generates an atmosphere of equalitarianism and nonelitism that taps into the environment of our Paleolithic ancestors, who evolved in what are believed to have been largely egalitarian bands and tribes.

This seems plausible enough and, sure, we infer from the egalitarian cultures of current hunter-gatherers that our Pleistocene ancestors had similarly egalitarian ways, but we don’t really know what the significance of this is. Numerous successful organizations – the American military comes to mind – have decidedly vertical structures. And soldiers too have ancestors who we infer lived in egalitarian cultures. So what does this “tap into” business really amount to? Some actual science would have been nice – plausibility is not a sufficiently high bar, support from serious academic studies is what Shermer’s hypotheses need. (When n=2 [Google + Enron] we can’t be really sure of anything). More importantly, Shermer should have explicitly warned his readers he was speculating. To be clear: I have nothing against speculation; it’s a valuable and important exercise. But it is vital to distinguish carefully between speculation and fact, between speculative extensions of theory and well-established theory.

A small matter also annoyed me a bit in the article: Shermer uses the term “evolution” in several distinct senses without clear distinction. There is vague metaphysical evolution, cultural evolution, biological evolution, and many others. Shermer invites misunderstanding by not being clear about which sense he’s referring to.

Lastly, Shermer’s contention that Google is a paragon of goodness (and thus an illustration of his evolutionary speculations) is vulnerable to the observation that the company doesn’t always behave as advertised. Google, let’s not forget, conveniently disregarded its principles for access to the Chinese market (among many other lapses, as Shermer himself documents). But his response to this problem is as lame as it comes, “Controversies of this nature are inevitable for any company that grows as rapidly as Google has, and no matter how lofty a company philosophy may be, perfection will always be an unattainable goal.” Human aren’t perfect. Great. But we knew that already. What happened to Shermer’s hypothesis that there is an evolutionary reason that “don’t be evil” breeds business success? Scientists don’t get to rationalize away inconvenient facts. (To be fair, this problem doesn’t implicate the contention that aspects of the “don’t be evil” philosophy cultivate an internal corporate structure conducive to business success. Shermer, however, unwisely defends a broader hypothesis at the end of the article).

Pravda silliness

The Russian online newspaper Pravda (ironically, "The Truth"; a distant descendant of the Pravda of the Communist era) is well known for being, well, crazy. My two favorite recent examples are "Centaurs appeared after copulation between humans and animals" and "Dolphins used to look like humans and lived in Atlantis". As I said, crazy. Now, oh the shock!, Pravda has published an embarrassingly naive article in defense of intelligent design. Frankly, the piece simply does not deserve a rational response - it rehearses the well-worn arguments we've heard hundreds of times from the evolution-deniers. My favorite part:

Trust me, Dawkins and all the evolutionists put together can't hold a candle to the scientific genius of Dr. Gish. Just read one of Dr. Gish's books and you'll see why. Dr. Gish has successfully debated hundreds of evolution scientists in secular colleges and universities across the nation over the past two decades, and students have consistently voted him the winner in all of those debates. Don't try looking for this news in the main stream media. You won't find it there anymore than you'll find a half-evolved chipmunk running around in your backyard!

Oh, we should 'trust him'! Right...

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.

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:

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. 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.

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:

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).

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.

Pinker, S. (2002) The Blank Slate: The Modern Denial of Human Nature (London: Penguin).