According to SMU Associate Professor of Psychology Norman Li, one of the easiest ways to tell if someone likes you is if they laugh at your jokes, or try to make you laugh. Li co-authored a study, An Evolutionary Perspective on Humour: Sexual Selection or Interest Indication, about how humour affects relationships by evaluating the way 46 undergraduates, both male and female, interacted with one another. The researchers found that "initiation of humour depended more on attraction and satisfaction than did general conversation. That is, when not attracted or satisfied, people reported being less likely to initiate humour. However, when attracted or satisfied, people reported being more likely to initiate humour than conversation."