A result the media loves to report is that people who study economics are more likely to react like jerks when asked to respond to game theoretic predicaments like the prisoners’ dilemma. Are economists naturally mean? I can’t rule it out, but I always thought a more likely explanation was that they have just thought about these puzzles ahead of time, and simply respond with a memorised ‘correct’ answer, such as the Nash equilibrium. So I was glad to see this paper in Nature finding that anyone who has a while to think about how to react to these situations also becomes more selfish:

Cooperation is central to human social behaviour. However, choosing to cooperate requires individuals to incur a personal cost to benefit others. Here we explore the cognitive basis of cooperative decision-making in humans using a dual-process framework. We ask whether people are predisposed towards selfishness, behaving cooperatively only through active self-control; or whether they are intuitively cooperative, with reflection and prospective reasoning favouring ‘rational’ self-interest. To investigate this issue, we perform ten studies using economic games. We find that across a range of experimental designs, subjects who reach their decisions more quickly are more cooperative. Furthermore, forcing subjects to decide quickly increases contributions, whereas instructing them to reflect and forcing them to decide slowly decreases contributions. Finally, an induction that primes subjects to trust their intuitions increases contributions compared with an induction that promotes greater reflection. To explain these results, we propose that cooperation is intuitive because cooperative heuristics are developed in daily life where cooperation is typically advantageous. We then validate predictions generated by this proposed mechanism. Our results provide convergent evidence that intuition supports cooperation in social dilemmas, and that reflection can undermine these cooperative impulses.

A take-away would be that if you want someone to cooperate with you, you could put them in a situation where they need to make a decision on the spot. And if you want to come across as a naturally nice guy, go with your cooperative instincts and don’t think too much. Greater selfishness should be expected as a downside to letting people go into a detailed ‘near’ mode, where they concretely reflect on strategic choices and the likely outcomes. Calculation makes you calculating.

What about those brave behavioural economists, sent onto the front lines to study human psychology? Maybe they should ask for extra pay to compensate for the risk their work presents to their personalities.