Primate innovation: Sex, age and social rank differences

Analysis of an exhaustive survey of primate behavior collated from the publ ished literature revealed significant variation in rates of innovation amon g individuals of different sex, age and social rank. We searched approximat ely 1,000 articles in four primatology journals, together with other releva nt databases, for examples of innovation. The reported incidence of innovat ion is higher in males and adults, and lower in females and nonadults, than would be expected by chance given the estimated relative proportions of th ese groups. Amongst chimpanzees, the only species for which. there are suff icient data to consider alone, there is a similar sex difference in the pro pensity to innovate, but no effect of age. Chimpanzees of low social rank a re reported as innovators more frequently than high-ranking chimpanzees are . Male chimpanzees innovate more often than females in sexual, courtship, m ating and display contexts; that is, in contexts likely to increase access to mates. The largest number of recorded observations are in the foraging c ontext, wherein contrary to expectations, there is no evidence for female c himpanzees exhibiting more innovation than males. The study is the first ex tensive investigation of behavioral innovation in primates and provides evi dence that much individual variation in the propensity to innovate can be e xplained in terms of sex, age, and social rank.