The first study of the heritability of general intelligence in chimpanzees shows that bright parents tend to produce bright kids. The original research was published in an essay called "Chimpanzee Intelligence Is Heritable" in the journal Current Biology by William D. Hopkins, Jamie L. Russell, and Jennifer Schaeffer. The summary reads as follows:
The role that genes play in human intelligence or IQ has remained a point of significant scientific debate dating back to the time of Galton [ 1 ]. It has now become increasingly clear that IQ is heritable in humans, but these effects can be modified by nongenetic mechanisms [ 2–4 ]. In contrast to human IQ, until recently, views of learning and cognition in animals have largely been dominated by the behaviorist school of thought, originally championed by Watson [ 5 ] and Skinner [ 6 ]. A large body of accumulated research now demonstrates a variety of cognitive abilities in nonhuman animals and challenges traditional behaviorist interpretations of performance [ 7, 8 ]. This, in turn, has led to a renewed interest in the role that social and biological factors might play in explaining individual and phylogenetic differences in cognition [ 9 ]. Specifically, aside from early attempts to selectively breed for learning skills in rodents [ 10–12 ], studies examining the role that genetic factors might play in individual variation in cognitive abilities in nonhuman animals, particularly nonhuman primates, are scarce. Here, we utilized a modified Primate Cognitive Test Battery [ 13 ] in conjunction with quantitative genetic analyses to examine whether cognitive performance is heritable in chimpanzees. We found that some but not all cognitive traits were significantly heritable in chimpanzees. We further found significant genetic correlations between different dimensions of cognitive functioning, suggesting that the genes that explain the variability of one cognitive trait might also explain that of other cognitive traits.
The essay itself and numbered references are available only to subscribers. However, a good review can be found in a piece by Andy Coghlan called "Chimpanzee Brain Power Is Strongly Heritable" in New Scientist (the title of the print version is titled "Intelligence Runs in Chimp Families Too"). Other summaries can be found here.
Ninety-nine chimpanzees were studied on a series of 13 cognitive tasks. Based on their data, Dr. Hopkins and his colleagues "estimate that, similar to humans, genetic differences account for about 54 percent of the range seen in 'general intelligence' – dubbed 'g' – which is measured via a series of cognitive tests." Dr. Hopkins notes, "Our results in chimps are quite consistent with data from humans, and the human heritability in 'g.' The historical view is that non-genetic factors dominate animal intelligence, and our findings challenge that view."
Other researchers agree. Renowned researcher Robert Plomin, of King's College London, notes, these data "are bang on with human results in showing substantial 'g' and in showing that results in nearly all of the tests are significantly heritable." Dr. Plomin also says, "the study suggests the range of cognitive abilities tested in the chimps are influenced by the same suites of genes."
I look forward to more research in this fascinating area on a broader range of nonhuman animals.
Marc Bekoff's latest books are Jasper's story: Saving moon bears (with Jill Robinson; see also), Ignoring nature no more: The case for compassionate conservation (see also), and Why dogs hump and bees get depressed (see also). Rewilding our hearts: Building pathways of compassion and coexistence will be published fall 2014. (marcbekoff.com; @MarcBekoff)