Cross-Species Analysis of Adaptive Choice

Pigeon artHow do people and other animals make decisions about different courses of action? Research in our lab has pursued such topics with human and animal subjects, aiming to bridge the methodological gap that has separated previous species comparisons. We have done so both by using “animal-like” reward systems with human subjects and “human-like” reward systems with animals. In general, we have found that reducing these procedural differences brings behavior of different species into better accord. It also has shed light on some important differences between species.

Impulsivity and Self-control

Under what conditions do people and other animals forego immediate but smaller rewards in favor of remote but ultimately larger rewards? How are such choices affected by the nature of the reward—primary (hedonic) versus secondary (symbolic) rewards? How are such choices affected by the magnitude (size) of the reward? For humans, under what conditions might verbal-hypothetical choices serve as an adequate substitute for choices with actual outcomes?

Risky Choice

Under what conditions do people and other animals prefer a certain payoff (e.g., a single morsel of food, a $50 cash prize) to a potentially larger but uncertain payoff (e.g., equal chances at nothing or a large cache of food, a $100 prize)? How are such choices affected by energy budget, or income? Does it matter if the choices are framed as involving gains (e.g., income added) versus losses (e.g., income removed)? How might lab models of risky choice relate to gambling problems outside the lab?

Persistence and Sunk Costs

Under what circumstances do people and other animals persist in a losing endeavor (e.g., investing in a depleting path of prey, a losing stock) versus switching to something potentially better (or possibly worse)? What effect does work or time required to change paths (e.g., a penalty for withdrawal) have on the decision to persist? What role does work or time already invested in the task (i.e., sunk costs) play in the decision to persist? How are such decisions affected by prior behavioral history?