From Outside In:
Another outrageous study completely overlooks the problem of stereotype threat.
That study as reported in Nature:
Study shows that about half of the animals’ intellect is heritable.
10 July 2014
For chimps, nature and nurture appear to contribute equally to intelligence.
Smart chimpanzees often have smart offspring, researchers suggest in one of the first analyses of the genetic contribution to intelligence in apes. The findings, published online today in Current Biology, could shed light on how human intelligence evolved, and might even lead to discoveries of genes associated with mental capacity.
A team led by William Hopkins, a psychologist at Georgia State University in Atlanta, tested the intelligence of 99 chimpanzees aged 9 to 54 years old, most of them descended from the same group of animals housed at the Yerkes National Primate Research Center in Atlanta. The chimps faced cognitive challenges such as remembering where food was hidden in a rotating object, following a human’s gaze and using tools to solve problems.
A subsequent statistical analysis revealed a correlation between the animals’ performance on these tests and their relatedness to other chimpanzees participating in the study. About half of the difference in performance between individual apes was genetic, the researchers found.
In humans, about 30% of intelligence in children can be explained by genetics; for adults, who are less vulnerable to environmental influences, that figure rises to 70%. Those numbers are comparable to the new estimate of the heritability of intelligence across a wide age range of chimps, says Danielle Posthuma, a behavioural geneticist at VU University in Amsterdam, who was not involved in the research.
[From Outside In] “Hopkins et al conclude (un-shockingly):”
Finally, from an evolutionary standpoint, the results reported here suggest that genetic factors play a significant role in determining individual variation in cognitive abilities, particularly for spatial cognition and communication skills. Presumably, these attributes would have conferred advantages to some individuals, perhaps in terms of enhanced foraging skills or increased social skills, leading to increased opportunities for access to food or mating … These individuals would have then potentially had increased survival and fitness, traits that would have become increasingly selected upon during primate evolution, as has been postulated by a number of theorists, going all the way back to Darwin …