 Cosmides (see e.g. 1989) defends a hypothesis in evolutionary psychology that we have a cheater-detection module.[10] This module is hypothesized to underlie important components of our behavior in moral domains and fits with the massively modular view of our psychology in general. Cosmides (along with Tooby) argues that cheating is a violation of a particular kind of conditional rule that goes along with a social contract. Social exchange is a system of cooperation for mutual benefit and cheaters violate the social contract that governs social exchange (Cosmides and Tooby 2005). The selection pressure for a dedicated cheater-detection module is the presence of cheaters in the social world. The cheater-detection module is an adaptation that arose in response to cheaters. The cheater-detection hypothesis has been the focus of a huge amount of critical discussion. Cosmides and Tooby (2008) defend the idea that cheat detection is modular over hypotheses that more general rules of inference are involved in the kind of reasoning behind cheater detection against critics Ron Mallon (2008) and Fodor (2008). Some criticism of the cheater-detection hypothesis involves rehashing criticisms of massive modularity in general and some treats the hypothesis as a contribution to moral psychology and invokes different considerations. For example, Mallon (2008) worries about the coherence of abandoning a domain general conception of ought in our conception of our moral psychology. This discussion is also ongoing. (See e.g. Sterelny 2012 for a selection of alternate, non-modular explanations of aspects of our moral psychology.)