Is cultural evolution always fast? Challenging the idea that cognitive gadgets would be capable of rapid and adaptive evolution

Against the background of “arms race” style competitive explanations for complex human cognition, such as the Social Intelligence Hypothesis (Byrne and Whiten in Machiavellian intelligence, Oxford University Press, Oxford, 1988; Humphrey, in Bateson PPG, Hinde RH (eds) Growing points in ethology, Cambridge University Press, pp 303–317, 1976; Jolly in Science, 10.1126/science.153.3735.501, 1966), and theories that tie complex cognition with environmental variability more broadly (Godfrey-Smith in Complexity and the function of mind in nature, Cambridge University Press, 1996, in Sternberg R, Kaufman J (eds) The evolution of intelligence, Lawrence Earlbaum and Associates, 2001), the idea that culturally inherited mechanisms for social cognition would be more capable of responding to the labile social environment is a compelling one. Whilst it is tempting to think that the evolvability of culturally inherited cognitive mechanisms such as Cecilia Heyes’ (2018) cognitive gadgets would be akin to culturally inherited tools like axes or canoes (i.e., relatively easy to modify to adaptive benefit, and relatively robustly inherited), I draw on established theory in evolutionary developmental biology to show that this is a mistake. Their causal translucency, along with the degree to which they would be integrated within the organism, make cognitive gadgets far more like genetically inherited traits with respect to their evolvability. Consequently, their evolution is unlikely to be particularly fast or nimble. In making clear the constraints on the evolution of culturally inherited cognition and how they must influence our theorising the discussion also highlights the value of thinking about evolvability in this domain.