Abstract: Homo economicus belief is the basic humanity hypothesis of economics, which assumes that human beings are rational decision makers who have the motivation to maximize their own self-interest. Previous literature revealed that homo economicus belief would inhibit trust. Those studies first activated college students' homo economicus belief by concept activation methods and mindset activation methods. It was found that participants' trust was inhibited by the activated belief. However, those studies cannot affirm that it was the homo economicus belief was activated in their priming tasks. Moreover, the college students in their studies had little economic experiences which may impede the potential validity of the results. Therefore, the effect of homo economicus belief on trust should be confirmed further. Finally, several studies had revealed that parents' trust can transmit to their children and individuals' selfish behaviors could inhibit observers' trust. Therefore, parents' homo economicus belief may inhibit children's trust. Based on a Chinese sample of 351 parents-child pairs, this study aimed to examine whether parents' homo economicus belief could affect their own trust and their children's trust. The study first developed a scale of homo economicus belief which contains two subscales:selfish and rational, and then collected parents' homo economicus belief, and then collected parents' and children's trust levels in investment game questionnaires. Each child was asked to decide how many chocolates would they like to send to a strange child and to guess how many chocolates would the strange child return to them. Each parent was asked to decide how much money would they like to send to a stranger and to guess how much money would the stranger return to them. Both the amounts of money and chocolates that participants sending and estimating to be returned was used to measure the level of interpersonal trust. The results showed that (1) the scale of homo economicus belief had good reliability and validity. (2) Both the parents and the children exhibited trust to some extent in the investment game questionnaires. (3) There was no significant gender difference between parents' homo economicus belief, parents' trust, and children's trust. (4) Parents' homo economicus belief can negatively predict their trust levels:the investment money and the estimated returning money. (5) Gender of the child moderated the effect of parents' homo economicus belief on children's trust. Parents' homo economicus belief can predict sons' trust (i.e., the investment chocolates), whereas they did not for daughters. This study confirms the previous literature and improves the understanding of the effect of homo economicus belief on trust.

Key words: homo economicus belief, trust, investment game