As We Build our World We Build our Minds:  The Causal Role of Technology in the Development and Evolution of Human Psychological Traits

Do genes or environments have more of a role to play in the development of psychological traits? The nature versus nurture debate takes many forms and recent developmental systems arguments consider the roles of developmental resources to be inextricably linked. In this thesis I show that some elements of human culture, specifically technologies, play a privileged role in psychological development. Moreover, as we invent new technologies, we change the developmental environment for the present and subsequent generations, thereby causing evolution of the mind. I begin by outlining evidence, which shows that culture, and technology in particular, cause novel psychological traits to develop. Then I explain the evolutionary dynamics by which novel technologies and traits co-elaborate each other. The brain has evolved adaptations for plasticity and responds to environmental challenges in novel ways during development. I also show that brains often integrate with the material world, incorporating symbols, technologies and other artefacts as part of distributed information processing systems. Having demonstrated that technology has a causal role to play in cognitive development and function, I then move on to explain how we can distinguish among causal roles and thereby favour some causes over others in explanations of the development of traits. Beginning with Woodward’s analysis of three dimensions of biological causation, I build a concept space and incorporate a fourth dimension of causation. This modified four-dimensional concept space of causal roles allows us to categorize and distinguish the causal role of genetic and non-genetic developmental resources. It turns out that, with respect to some questions or effects we are interested in, genes are important, and with respect to many other effects or developmental outcomes, cultural technologies are more privileged causes. I illustrate the use of this causal analysis tool by explaining the development of critical thinking skills. I conclude by arguing that the privileged role of technology in psychological development may help to explain two problems in human prehistory. First, it helps to explain why there was a lag between Homo sapiens becoming anatomically modern and only later becoming behaviourally modern, and second, it helps to explain the mysterious extinction of the Neanderthals.