Abstract:
People’s political attitudes and values vary. Research over the last fifty years has suggested
that this variation is due to differences in two foundational dimensions of political ideology,
often labelled as economic and social conservatism, or social dominance and authoritarianism.
While the existence of these two dimensions of political ideology is supported by
evidence from political, social, moral, and cross-cultural psychology, less work has examined
the essential nature of the two dimensions or asked why this particular two-dimensional
structure organises political attitudes and values. In this thesis, I outline a dual evolutionary
theoretical framework to understand the two dimensions of political ideology in humans.
Synthesising and expanding on existing evolutionary approaches to politics, I argue that the
two dimensions of political ideology have emerged from two key shifts in the evolution of
human group living. First, humans began to cooperate more across wider interdependent
networks and share the spoils of cooperation more evenly. Second, humans became more
committed to group viability, conforming to social norms in culturally marked groups and
punishing norm-violators. These key shifts correspond to economic and social conservatism,
respectively. I test this theory by leveraging empirical tools from behavioural economics.
Across several studies using abstract incentivised behavioural tasks, I show that cooperative
and group conformist preferences reliably predict economically and socially conservative
views. By supporting the dual evolutionary framework for political ideology, these results
show how ancient social drives that evolved to help us navigate the challenges of human
group living continue to shape the political landscape even today.
