1. Current State of Play Cognitive psychology / neuroscience: –Increasingly rigorous models of individual decision making –Virtual ignorance (and ignoring) of social factors Social psychology: –Rich phenomenology and qualitative analysis of social factors influencing individual and group decision making –Relative absence of formal models

2. Goals Construct simple decision making tasks, for which we have a well specified (formal) models, in which we can control and examine social factors that affect performance Understand the influence of social factors/interactions on individual and group performance in terms of formally rigorous models of decision making

3. A decision task A B

4. Simple reward structure 0 0.25 0.5 0.75 1 00.250.50.751 % A Reward Reward A Reward B Average

5. More interesting structure (“Rising Optimum Task”) 0 0.25 0.5 0.75 1 00.250.50.751 % A Reward Reward A Reward B Average

6. Advantages Existing formal model of decision process –Stochastic choice based on biased DDM –Biases accrue based on reinforcement (temporal differences) learning algorithm Useful for studying exploration vs. exploitation –Task parameters can be titrated so that most subjects find the local maximum but some (who explore) find global maximum Laboratory controlled environment for studying social factors –Parameterize so that most subjects find local maximum –Control flow of social information (e.g., choices made and/or rewards received by other players) and examine influences on group vs. individual behavior (comparison) –Amenable to formal modeling (e.g., counterfactual RL)