The evolutionary psychology of war

Nothing too shocking here for students of evolutionary psychology but it’s always interesting to see real world examples of how our shared behavior. There is a new book by Sebastian Junger called War, in which he recounts how men do not fight for larger ideological goals (eg. “a safer Iraq”, “finding Bin Laden”) but instead they can overcome fears because “they’re more concerned about their brothers than what happens to themselves individually”. Here’s Junger on Good Morning America:

After the jump some more from Junger and a nice talk from Robert Sapolsky about similar behaviors in chimps.

Continue reading

Henry Markram on TED – video online

We had read that Dr. Henry Markram of the Blue Brain project had given a talk at TED (technology, entertainment, design), but the video wasn’t released until this month.  This talk is geared towards a general audience, rather than getting into the specific details of the Blue Brain project, as he has before.  It is engaging and includes many suggestions towards the future of neuroscience and AI.

Watch it online at the TED website.

Evidence of similar linguistic capabilities in Neaderthals

Apparently, in a few years, we will be able to bring Neaderthals back to life with the complete Neaderthal genome [NYT]. Currently, there is good sequence data available over 63% of the genome. (I’m amazed that, given fragmented DNA from bone, Neanderthal sequence can be distinguished from human DNA contamination but perhaps this problem is solved by having high enough coverage/multiple fragments of the same region.)

Also, it looks like Neanderthals share the FOXP2 variant that humans have:

Archaeologists have long debated whether Neanderthals could speak, and they have eagerly awaited Dr. Pääbo’s analysis of the Neanderthal FOXP2, a gene essential for language. Modern humans have two changes in FOXP2 that are not found in chimpanzees, and that presumably evolved to make speech possible. Dr. Pääbo said Neanderthals had the same two changes in their version of the FOXP2 gene. But many other genes are involved in language, so it is too early to say whether Neanderthals could speak.

UPDATE: A few days ago, I heard Wolf Enard, one of Paabo’s postdocs, speak on a fascinating project, where human version of FOXP2 was knocked in to mice (replacing the endogenous mouse version). Although the phenotypic effects were subtle, the approach itself is quite revolutionary: Putting human versions of genes into model organisms to see how the subsequent evolution of the gene changes its function. I wonder what other genes might be amenable to this approach.

Bad-ass squirrels

In the new issue of PNAS, a totally awesome discovery about an infrared inter-species signalling system:

Ground squirrels not only heat up their tails to deter snake attacks — but they also seem to use the strategy selectively against infrared-sensitive snakes — leading us to the ultimate conclusion that when the bees are gone, the squirrels will inherit the earth…

You can check out an infrared-eye-view of squirrel/snake battles here because I don’t know how to post movies on the internet yet


A ubiquitous human parasite that shapes human culture?

In the provocative-hypothesis-of-the-week department:

Kevin Lafferty, a parasitologist, has put forth the idea that a fairly ubiquitous parasite (infecting O(10%) of Americans, and up to 2/3 of people in places like Brazil) is responsible for some of the diversity of human culures (1). The parasite uses common housecats to increase its transmission to the next host in the life cycle, and has a subtle effect on human personality, with some studies claiming that it even causes neuroticism, and even schizophrenia. (One clinical report (2) claims that “subjects with latent toxoplasmosis had higher intelligence [and] lower guilt proneness.” Hmm!)

Anyway, Lafferty noted that toxoplasmosis varies in prevalence from world region to world region, and then tries to draw correlates between these prevalences and local cultures:

“Drivers of the geographical variation in the prevalence of this parasite include the effects of climate on the persistence of infectious stages in soil, the cultural practices of food preparation and cats as pets. Some variation in culture, therefore, may ultimately be related to how climate affects the distribution of T. gondii, though the results only explain a fraction of the variation in two of the four cultural dimensions, suggesting that if T. gondii does influence human culture, it is only one among many factors.”

I wonder how one could test this hypothesis? Look for recent immigrants from one culture to another, who have lower Toxoplasmosis incidence? (Preferably finding populations that go in opposite directions, as a control.) Track culture change vs. migration vs. climate change?

Unlikely, perhaps. But nice that people are still thinking big 🙂


(1) Lafferty, K
Can the common brain parasite, Toxoplasma gondii, influence human culture?
Proceedings of the Royal Society B: Biological Sciences

Picked up by the popular press here

(2) Flegr J, Havlicek J.
Changes in the personality profile of young women with latent toxoplasmosis.
Folia Parasitol (Praha). 1999;46(1):22-8.

Personality in animals

The Animal Self – New York Times

Interesting read on the return of personality psych (and the use of the term “personality”) to ethology.

Some tidbits:

It was back in 1991 that Anderson and Jennifer Mather, a psychologist from the University of Lethbridge in Alberta, Canada, first decided to undertake a joint personality study of 44 smaller red octopuses at the aquarium as a way to begin to codify and systematize what they thought they had been observing. Using three categorizations from a standard human-personality-assessment test – shy, aggressive and passive – their data would ultimately show that the animals did consistently clump together under these different categories in response to various stimuli, like touching them with a bristly test-tube brush or dropping a crab into the tank.

“The aggressive ones would pounce on the crab,” Anderson told me. “The passive ones would wait for the crab to come past and then grab it. The shy animal would wait till overnight when no one was looking, and we’d find this little pile of crab shell in the morning.”

Anderson and Mather’s resulting 1993 paper in the Journal of Comparative Psychology, entitled “Personalities of Octopuses,” was not only the first-ever documentation of personality in invertebrates. It was the first time in anyone’s memory that the term “personality” had been applied to a nonhuman in a major psychology journal.


Alison Bell has done related experiments with sticklebacks. It has long been clear to researchers that fish that have lived for many generations in the proximity of dangerous predators are less bold and less aggressive than animals that have lived relatively risk-free. What Bell discovered is that those cautious tendencies outlast the presence of risk, even by a generation. When she moved sticklebacks who had always lived in a high-risk environment into a low-risk environment, she found that not only did they retain their cautious tendencies, but so did their offspring. Even fish raised from birth in a low-risk environment behave more fearfully if raised by a particularly vigilant father from a high-risk background.

“There’s definitely the effect of genetic difference,” Bell explained, “but there’s also the effect of what is experienced as they grow up. Genotype and environment interactions make it difficult to detect the effects of genes, because you have to take the environment into account. This is annoying to geneticists.” To scientists like Bell who are studying the interplay of genes and environment, however, it is of profound interest.