In this thesis the effect of gender priming on economic decision-making was researched. Data was gathered using a questionnaire with 3 different priming tasks. Questions about 5 different areas of economic behaviour are researched. Eighty-seven people participated in the online experiment. It was found that male stereotype priming had a large and significant effect on the level of Trust a subject had that another person would cooperate. Furthermore a slightly less significant effect of male-priming on Cooperation was found, but the effect of gender priming was not clear in other areas. Further research could be done to test the priming instruments, to search for more results on Trust and to explore the use of same-sex or opposite-sex priming in economic research.