Publication Date



Open access

Embargo Period


Degree Type


Degree Name

Doctor of Philosophy (PHD)


Psychology (Arts and Sciences)

Date of Defense


First Committee Member

Michael McCullough

Second Committee Member

Heather Henderson

Third Committee Member

Daniel Messinger

Fourth Committee Member

Debra Lieberman

Fifth Committee Member

William Searcy


This dissertation was designed to examine whether people feel more gratitude in response to benefits rendered by strangers and acquaintances than in response to benefits provided by established reciprocal relationship partners and genetic relatives, and whether the gratitude experienced in response to benefits provided by those novel non-kin benefactors is more likely to lead to motivation to reciprocate than is the gratitude elicited by benefits rendered by genetic relatives and established reciprocal altruism partners. It was hypothesized that gratitude would be more salient when benefits are rendered by strangers and acquaintances than by well-known individuals in already-established reciprocal relationships or in kin relationships. Using self-report questionnaires from 128 University of Miami students, this study revealed that benefit recipients reported stronger urges to reciprocate, engaged in more reciprocal prosocial behavior, and were more likely to respond to the feeling of gratitude with prosocial reciprocation when benefitted by friends and siblings than when benefited by acquaintances. Additionally, post-benefit contact significantly predicted reciprocal action, and post-benefit contact mediated the effects of relationship type on recipients’ reciprocal actions and urges to reciprocate. Although findings did not support the original hypotheses, these findings indicate that there are other factors correlated with relationship type that influence an individual’s likelihood of feeling grateful and reciprocating. To the extent that these factors (e.g., a high likelihood of future post-benefit interaction) are present, they might prevent mechanisms designed for reciprocal altruism from creating internal motivations to engage in reciprocal prosocial behavior.


gratitude; reciprocal; altruism; prosocial behavior