Online labor markets such as Amazon Mechanical Turk (MTurk) off er an unprecedented opportunity to run economic game experiments quickly and inexpensively. Using Mturk, we recruited 756 subjects and examined their behavior in four canonical economic games, with two payoff conditions each: a...

We explore how risk-taking in the card game contract bridge, and in a financial gamble, correlate with variation in the dopamine receptor D4 gene (DRD4) among serious tournament bridge players. In bridge risk-taking, we find significant interactions between genetic predisposition and skill....

Online labor markets have great potential as platforms for conducting experiments. They provide immediate access to a large and diverse subject pool, and allow researchers to control the experimental context. Online experiments, we show, can be just as valid - both internally and externally - as...

It has been argued that punishment promotes the evolution of cooperation when mutation rates are high (i.e. when agents engage in ‘exploration dynamics’). Mutations maintain a steady supply of agents that punish free-riders, and thus free-riders are at a disadvantage. Recent experiments,...

Cooperation is central to human societies. Yet relatively little is known about the cognitive underpinnings of cooperative decision-making. Does cooperation require deliberate self-restraint? Or is spontaneous prosociality reined in by calculating self-interest? Here we present a theory of why...

Behavioral and economic analysis of law fundamentally depends on understanding what motivates individual actors. While it is often assumed that people care only about maximizing their own monetary payoff, recent experimental work has challenged this assumption. A canonical example involves...

We review two fundamentally different ways that decision time is related to cooperation. First, studies have experimentally manipulated decision time to understand how cooperation is related to the use of intuition versus deliberation. Current evidence supports the claim that time pressure (and,...

What is the extent and nature of religious prosociality? If religious prosociality exists, is it parochial and extended selectively to co-religionists, or is it generalized regardless of the recipient? Further, is it driven by preferences to help others or by expectations of reciprocity? We...

Recent work using decontextualized economic games suggests that cooperation is a dynamic decision-making process: automatic responses typically support cooperation on average, while deliberation leads to increased selfishness. Here we performed two studies examining how these temporal effects...

We extend the dual-self model to include altruistic preferences. This explains (1) why people may have preferences for equality in the laboratory but not in the field, (2) why intermediate donations may occur in dictator games, (3) why cognitive load and time pressure may increase giving, and...