Define Cosmides’ Social Contract/Social Exchange theory

Define Cosmides’ Social Contract/Social Exchange theory (include the cost-benefit rule and detection of cheaters’ mechanism). Paragraph 2: Make a critique of this work (i.e., discuss a major problem with Cosmides’ work). Paragraph 3: How did Gigerenzer and Hug use perspective effects to create a more elegant experimental design that supports Cosmides’ theory?