The question of ‘what makes us human’ is one that has intrigued theologians and philosophers alike for hundreds of years. One aspect of human behavior which appears unparalleled in the Animal Kingdom is our kindness and regard for other individuals. However, recent studies have shown that this prosocial proclivity isn’t always evident in young children, raising intriguing questions as regards the developmental origins of human generosity. The current project aims to capitalize on the expertise of the PI (Nicola McGuigan) in both prosociality research and social learning research in order to perform a series of interlocking studies detailing social influences on prosocial behavior. The project will ask for the first time: 1) whether donor individuals (4- and 7-year-old children) will vary in their level of prosociality in accordance with the prior behavior of their peers (i.e., show higher levels of prosociality towards individuals with a reputation for generosity), before going on to ask, 2) whether donor individuals will conform to the level of generosity (generous or selfish) shown by the majority of a small sub-set of their peer group. These initial studies will be complemented by experiments that will employ novel diffusion methodologies in order to examine whether generosity, or indeed selfishness, can be transmitted across entire groups of children. This novel integration of prosociality, social learning and conformity in combination with new and exciting methodologies for exploring cultural transmission will not only lead to high quality publications it will also be of interest to scientists in related fields, and combined with the proposed public engagement activities will lead to enduring impacts for both academic and non-academic audiences alike.