The robustness of trust and reciprocity across a heterogeneous US population

Experimental evidence on gender differences demonstrates that women are generally less trusting and more reciprocating than men in Investment Games. However, existing studies typically use a narrow population consisting of college students. To test the robustness of these findings, we report on an experiment using 18-84-year old participants recruited from an online panel. While trusting gender differences are robust across age, with women less trusting than men, reciprocating behavior is not robust across age; gender differences in reciprocating behavior depend on age and amounts received in a complex manner. Regarding trusting behavior, we also find that men and women of all ages trust women and older people more than men and younger people. To understand trust better, we collected socio-economic and demographic information and experimentally measured how much subjects expected different partner types would return. While socio-economic and demographic information explain little of the trusting and reciprocating behavior, expectations explain nearly 50 percent of the reason women trust less than men and why more is sent to women and older people. However, even after controlling for expectations, gender and age differences remain significant in explaining trusting behavior. (C) 2008 Elsevier B.V. All rights reserved.