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Archive for the ‘intelligence’ Category

humphrey.JPGIt was twenty years ago today. Sgt. Pepper taught the band to play.

Actually, last year it was 30 years ago that Nicholas Humphrey published his seminal paper “The social function of intellect” (pdf). Many people see this paper as the impetus to later work on the social brain hypothesis (pdf) and Theory of Mind. Humphrey suggested that, rather than the need for technology, it was in fact the need for advanced cognitive mechanisms for keeping track of conspecifics and interacting with other members of their social group that drove the expansion of brain and intelligence in hominids. This idea has provoked research into the role of cooperation and collaboration as well as deception and competition in primate social behaviour. It has prompted research into the importance of conspecifics being able to attend to a shared mental content. (Shared attention appears crucial to the transfer of knowledge in a social group, and is therefore probably a prerequisite for the establishment of cultural traditions.) Finally, it has been instrumental in getting neuroscientists interested in the neurobiological underpinnings of social cognition, including research into Theory of Mind and mirror neurons.

To commemorate Humphrey’s paper and track the above-mentioned ensuing research, the Royal Society of London staged a Dicussion Meeting last year. The papers presented at that meeting have now been published in the latest issue of the Philosophical Transactions of the Royal Society B. It is a veritable smorgardsbord of big names: There’s papers on social intelligence in birds, hyenas, dolphins and apes by, inter alia, Nathan Emery, Nicola Clayton, Kay Holekamp, and Richard Connor. Richard Byrne and Andrew Whiten discuss the animal cultures hypothesis. There’s papers by Michael Tomasello and Daniel Povinelli on ToM in primates. Vittorio Gallese explains the importance of mirror neurons, Chris Frith reviews what we know about the social brain, and Steven Mithen speculates that farming may have arisen from a misapplication of social intelligence. Naturally, Humphrey is also given the opportunity to revisit his 1976 paper.

If you are at all interested in the question of what makes some species social beings you will want to check out this issue.

-Martin

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einstein.jpgWhat characterizes Albert Einstein‘s brain? Why did he become a genius? Can we trace it down to brain-related factors? A growing literature on the relationship between intelligence and brain structure and function has demonstrated several relationships. Those studies, however, are typically based on comparison of brains of high versus mean IQ groups. Studying individual geniuses and what is special about their brains are rare in the scientific literature. However, there are a few exceptions.

In a study by Colombo et al in Brain Research Reviews, the brain of Albert Einstein is studied and compared to four age-matched individuals without any known neurological or psychiatric symptoms. The researchers found that

Einstein’s astrocytic processes showed larger sizes and higher numbers of interlaminar terminal masses, reaching sizes of 15 μm in diameter.

And they further notice that

These bulbous endings are of unknown significance and they have been described occurring in Alzheimer’s disease

…which would mean that, if anything, the size and number of interlaminal terminal masses in Einstein’s brain would make it more like an Alzheimer-patient than like a genius.

Colombo and colleagues are indeed sceptic about the findings and interpretations in the literature on Einstein’s brain. But why do this study in the first place? I’m baffled — to put it mildly — that this kind of study is published in a well-esteemed (well, any) scientific journal. This due to especially three factors relating to the validity of the study:

  1. There are only four control subjects. This provides no information about what the population as a whole looks like for the given brain measurement. IOW, we cannot know anything about the natural variance in the population of our measures, let alone know much about the mean value. Given this, the up-to-15-μm-diameter interlaminal terminal masses means nothing, since we cannot know anything about whether Einstein’s brain is special
  2. One is studying an old and degenerated brain. The fact that the study is of Einstein’s brain at a high age (76 years) seems irrelevant to discover what made his brain so special during the age at which he formulated and developed his theoretical ideas, i.e. decades earlier. This period not only includes the time at which he wrote about relativity, but also an earlier and less known period when he wrote the Annus Mirabilis Papers. This latter series of articles are concerned with the photoelectric effect, also recognized as papers that alone deserve a Nobel prize. And those papers were even written by Einstein during his spare time!
  3. Why not study a group of geniuses? Indeed, why only rely on one data point? Why not include a larger sample of geniuses, not only from physics, but from other sciences? Einstein was not the only genius around. Living in Denmark and passing through the Copenhagen University physics buildings regularly, I am immediately reminded of Niels Bohr, a contemporary to Einstein that matches Einstein’s genius in every respect. It would thus be much more interesting to see a group study of geniuses. It might be hard to do a genius post-morten study for both practical and ethical reasons, but one can do in vivo studies of today’s geniuses, right? One data point, even if it’s Einstein, is really not enough. Doing a group study we could also ask questions such as whether there are differences between male and female geniuses, or whether the develop and age different from the general population.

Einstein’s brain is indeed an interesting topic, but in order to make valid inferences from a study of his brain, we should consider including his brain among a number of related geniuses. Doing any kind of study of one genius’ brain is unlikely to produce any valid finding at all.

-Thomas

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