Date of Award

Spring 1-1-2012

Document Type


Degree Name

Doctor of Philosophy (PhD)


Psychology & Neuroscience

First Advisor

Leaf Van Boven

Second Advisor

Bernadette Park

Third Advisor

Peter McGraw

Fourth Advisor

Sona Dimidjian

Fifth Advisor

Nicholas Flores


When observing the prosocial acts of others, people tend to be very concerned with the reasons for act. A charitable donation motivated by concern for the charitable cause is seen as noble, while the same donation motivated by image enhancement is seen as disingenuous. In a series of six studies, participants consistently evaluated extrinsically motivated prosocial acts to be subjectively smaller and less impactful than the identical but intrinsically motivated act, and evaluated the extrinsically motivated actors less favorably than intrinsically motivated actors. These effects were robust across different prosocial domains and across different types of acts, including the donation of money and time and for conservation behaviors. These results demonstrate that motivation information causes people to violate strict adherence to principles of fungibility, using contextual information to evaluate equal fungible units differently. Two further studies establish that people will adjust their choices of products and resource allocation to punish extrinsically motivated actors and reward intrinsically motivated actors. The authors discuss these findings relative to formal principles of rationality, and propose an explanation of contextualized rationality. The implications of these findings for policy-making and implementation are discussed.