Showing posts with label Africa. Show all posts
Showing posts with label Africa. Show all posts

Wednesday, November 24, 2010

Lazy Linking

"Psychopathy seems to be caused by specific mental deficiencies"
  • The Economist reviews research that used the venerable Wason selection task to reveal psychopaths seem unable to understand social contracts. This suggests (albeit weakly) that psychopathy is a frequency-dependent adaptation. 
  • Time magazine profile of the courageous James Onen, head of Freethought Kampalaan organization dedicated to science and reason in a highly superstitious country.
    "The Shadow Scholar"
    • Disturbing Chronicle of Higher Education profile of an 'academic mercenary' paid to write essays and other academic work for students. Scary stuff.
    • It seems to me that there is little academics themselves can do about this problem. If I suspect a student has paid someone to do her work for her, then what? I... hack her email account? The only long-term solution, it seems to me, is to criminalize the companies that provide these services - after all, they're arguably committing (or at least abetting) fraud. When the companies' records are seized, guilty students should be tracked down and punished. Degrees should be withdrawn, etc. I'm not saying this will solve the problem completely, but it'll at least lessen it, and provide some deterrent. 
    "Freaks, Geeks, and Economists"
    • The subtitle says it all: "a study confirms every suspicion you ever had about high-school dating".
    • Fallacies categorized and their family relationships mapped. Good stuff. 
    "This Is Your Brain on Metaphors"
    • Robert Sapolsky does great work, and this piece is as good evidence of that as any. He reviews a bunch of research which demonstrates that the brain conflates the literal and metaphorical. That is, certain 'higher' mental functions (like morality) is simply bolted onto 'lower' mental functions (like disgust). 
    • "Nelson Mandela was wrong when he advised, “Don’t talk to their minds; talk to their hearts.” He meant talk to their insulas and cingulate cortices and all those other confused brain regions, because that confusion could help make for a better world."
    "Tanzania's first elected albino MP fears for life"
    • What's the harm? This. This is the harm. 
    • Quacks + poachers = rhinos in trouble.
    "Not so fast... What's so premature about premature ejaculation?"
    • Jesse Bering strikes again. Premature ejaculation from an evolutionary perspective... Be sure to read the incisive comments.
    • Profile of Arthur Goldstuck, premiere cataloger of South Africa's urban legends. I attended the book launch, and I've read his latest book (The Burglar in the Bin Bag). Very good stuff. 
    • Arthur is on Twitter as @art2gee and blogs at Urban Legends.
    "What’s In Placebos?"
    • Apparently placebos are not all alike. Steven Novella covers the fascinating details and discusses the consequences. 
    "Palestinian Blogger Angers West Bank Muslims"
    • It's not exactly surprising that an atheist is unwelcome in the West Bank, but (1) it's still lametable that he isn't but (2) heartening that he exists at all. 
    "10 Bizarre Medical Discoveries"
    • Sample: symptoms of asthma can be treated with a roller coaster ride... 
    "Kasparov versus the World"
    • The fascinating story of Gary Kasparov's epic game against the rest of the world (well, a huge number of chess players who collaborated online). Kasparov called it "the greatest game in the history of chess".
    "The glorious mess of real scientific results"
    • This is written by Ben Goldacre. Go, read.
    "Calculate the Effect of an Asteroid Impact on Earth"
    • Go on, what are you waiting for? You know you want to...
    "Putting a Hex on Hitler, 1941"
    • Life covers a batty attempt to defeat Hitler... with witchcraft. 
    "There Are 5,000 Janitors in the U.S. with PhDs"
    • :-(
    • Another Economist piece, this time a review of the book A Wicked Company: The Forgotten Radicalism of the European Enlightenment. According to the review, the book is the story of the salon presided over by the (unjustly forgotten - but not by me) Baron d'Holbach
    "The Fascinating Story of the Twins Who Share Brains, Thoughts, and Senses"
    Pretty / WOW / heh

    "'Dance Your Ph.D. 2010' Winner Announced"
    • This is just wonderful. Watch the video, srsly.
    "National Geographic's Photography Contest 2010"
    • Must see gorgeousness from Big Picture.
    "Wildlife through the lens"
    • Beautiful wildlife photography.
    "The Difference Between Jesus and Zombies"
    • heh
    "What I Think About Atlas Shrugged"
    • Sci-fi author John Scalzi rips into Ayn Rand. Hilarity results. 

    Monday, August 2, 2010

    Carnival of the Africans #15

    The 15th edition of the Carnival of the Africans is out over at Bomoko and other nonsense words. There is plenty of interest - aliens, SETI, muti killings, WEIRD subjects, etc. - so go check it out!

    Tuesday, July 20, 2010

    Depictions of violence in rock art

    A street fight, via Wikipedia.
    To understand the phenomena of murder, war, genocide, and other forms of human intraspecific violence, we need to know whether to invoke evolutionary biological explanations or restrict ourselves primarily to socio-cultural theories. If the incidence of violent conflict was high and recurrent for a substantial period during human evolution, and given that being killed drastically reduced fitness and killing may have increased it, then strong selective pressures would have favored physical and psychological adaptations to violence. Conversely, if interpersonal violence was rare or nonexistent until much more recently – until the rise of agriculture about 10,000 years ago, say – not enough time would have elapsed for natural selection to have forged significant new adaptations, and socio-cultural explanations of violence would thus predominate. (It should be noted, though, that recent human evolution has been very rapid, so this judgement may have to be revised in future as more evidence comes in). More precisely, whether adaptations to violence exist or not depends on the intensity of the selection pressures and their duration, and the intensity of the selection pressures is in turn a function of the frequency of violence and the magnitude of its impact on fitness. Thus, to determine the plausibility of positing traits that are adaptations to violence we need to know: (1) how frequent violence was, (2) whether it was recurrent in human evolutionary history and (3) how large its impact on inclusive fitness was.

    Determining (3), of course, depends in part on the values we assign to (1) and (2). Being killed before reproduction obviously reduced fitness to zero, and being killed after reproduction eliminated all the kin altruism the individual would otherwise have engaged in. The impact on fitness of being injured depended on the severity of the injury, but it seems clear it would have been negative and serious. What we need to deduce the magnitude of (3) over human evolutionary history, then, is sound empirical estimates of (1) and (2). Unfortunately, however, these estimates are extremely difficult to make because the available evidence is sparse and often ambiguous. Broadly speaking, there are two lines of evidence available to us: studies of contemporary hunter-gatherers and the paleoanthropological and archeological record. There are several controversies around both lines of evidence, but for this post I'll focus on one type of evidence from the archeological record: depictions of violence in rock art.

    A beautiful example of such a depiction is a San pictograph "Veg 'n Vlug" (Afrikaans: "Fight or Flight") that is near Clanwilliam in the Cederberg of South Africa. (Note: I've used the Auto-Level feature in Paint.NET to bring out some of the details):



    John Parkington describes (large pdf; pp. 62 - 65) the scene thus:
    The fight element is created by painting around a small recess in the rock surface to give the impression of a small cave from which a group of humans peer, one of them shooting arrows. A second group of humans, arranged as a procession and depicted apparently moving along a pair of red lines, face the cave occupants and also shoot arrows. From the ‘cave’ several people, most of them male, flee along more pairs of red parallel lines. One human figure, clearly lying prone is connected by these same lines to a strange seated  figure holding the end of the lines, neither of them directly connected with the cave itself. From the neck of the strange seated figure a single red line leads to another small figure with upraised arms.
    Contrary to the hypothesis - favored by neo-Rousseauians like Brian Ferguson - that human evolutionary history was entirely (or largely) peaceful, then, we have at least an existence proof of such violence. Or do we? Ferguson has argued that pictographs seemingly depicting violence should not be interpreted literally, but rather metaphorically. In other words, "Veg 'n Vlug" doesn't depict an actual event, the artists meant something else entirely, or is perhaps an attempt at sympathetic magic. (To be clear, as far as I know Ferguson has never written about this specific pictograph. I'm illustrating the kind of argument he's made about other rock art depictions of violence). And there are certainly aspects of "Veg 'n Vlug" that isn't literal. Parkington continues from the above quotation:
    This bald, but reasonably literal description gives no hint of the intriguing and enigmatic details that impart a deeper, but still obscure meaning to this apparently unified composition. Take the double red lines for example. They cannot, as might appear at first glance, be footprints or a path, because they connect the feet of those in the procession to the bow of one of the cave occupants and emerge from the bowstring to enter the mouth (or face) of the bow and arrow-wielding figure. The strange figure reeling in the lines from the feet of the prone, perhaps dead, figure cannot be manipulating footprints or a path in any literal way. It is likely that the double, parallel red lines are painted to illustrate some connectedness between people that is intangible but central to the meaning of the composition. The attachments to feet, hands, equipment and mouth probably indicate the nature of the connection but are not explicit enough to provide a definitive narrative.
    So what does this mean? Well, clearly, the pictograph cannot be strictly literal. Perhaps the artist(s) intended to convey some, now obscure, metaphorical meaning. Perhaps aspects of the drawing represent something abstract. Contra Ferguson et. al., though, I don't think it is reasonable to conclude that a metaphorical interpretation obviates a literal interpretation.

    Take my avatar and favorite painting, A Philosopher Lecturing on the Orrery by Joseph Wright:


    The painting has two, complementary, meanings. Whether Wright had in mind a specific instance of a scientist[1] demonstrating an orrery (a clockwork-driven model of the universe), it's clearly the kind of thing that went on at the time. That is, there certainly were orreries, scientists, and scientists demonstrating orreries and the painting represents an instance of the latter. The painting conveys much more than just 'such-and-such' happened, though. Many metaphorical interpretations are possible, naturally, but Wright seems to have intended it as a celebration of science, of the Enlightenment. The point could be argued, but suppose we agree A Philosopher represents the Enlightenment. Does that mean we have to abandon a literal reading? Insist that the painting tells us nothing about orreries and scientists? Obviously not. Literal and metaphorical representations can, and often do, co-exist.

    What this illustrates, I'm suggesting, is that however we interpret the non-literal aspects of "Veg 'n Vlug", we need not abandon a literal reading. In other words, even if there are abstract or metaphorical meanings we can assign to the pictograph, it still depicts two groups engaging in violence. It's necessary to go a step or two further, in fact. Not only can metaphorical and literal readings co-exist, we should apply Occam's Razor and favor a kind of interpretive parsimony: the simplest interpretation - the one that requires the fewest new assumptions - is likely the correct one. And in nearly all cases, the literal interpretation is the simplest.

    Whatever metaphorical or abstract readings we assign to any pictograph do not necessarily obviate literal interpretations. And interpretive parsimony - favoring the simplest possible interpretation - cautions against metaphorical readings in the first place, and demands especially strong evidence before we elevate metaphor over straightforward representation. In short, unless we have strong reasons to think otherwise, pictographs like "Veg en Vlug" represent evidence of ancient violence.

    ----
    [1] The word 'philosopher' at the time had multiple meanings, one of which was what we would now call a scientist.

    Tuesday, June 1, 2010

    African science blogrolling for June

    The updated African science and skepticism blog roll for June... If you know of blogs not listed here, please let me know. Also: add it to your blog! Do a post like this one! (Email me, and I'll send you the HTML). Note: I remove blogs that have been inactive for more than 6 months, so if you're no longer on the list and have resumed blogging, please email me.

    Video: Saving Africa's Witch Children

    Update: I see the video I embedded has been removed. There is, *cough*cough*, a torrent available...

    A documentary (embedded below, or click here) on one of the greatest tragedies of our time: witch hunts in Africa. The only appropriate response is burning indignation. (Note: you can download this video by following the link and creating an account with Vimeo).


    Saving Africa's Witch Children from Africa's Witch Children on Vimeo.

    See also my posts: "Human Sacrifice in Uganda" and "Witch Trials in Africa".

    Monday, March 1, 2010

    Carnival of the Africans #14

    Simon of Amanuensis has put up the 14th edition of the Carnival of the Africans, our humble effort to promote scientific and skeptical blogs from Africa. There are a bunch of very interesting posts to feast on, so do have a look! A selection: Mark from the Grumpy Old Man on the Lancet's retraction of the Wakefield paper and on a quack witchdoctor; Angela from The Skeptic Detective on the South African Society for Paranormal Research; and Simon himself on fMRI evidence for inequality aversion. My contributions to this edition were on deference and the importance of blinding...

    We do need hosts for future editions of the carnival, so if you'd like to take on the responsibility (it's fun...), have a look at the schedule, and drop me an email!