of the concept of spandrel and of the concept of exaptation explored by Stephen Jay Gould among others. Minimally counterintuitive concepts Concepts that mostly fit human preconceptions but break with them in one or two striking ways. These concepts are both easy to remember (thanks to the counterintuitive elements) and easy to use (thanks to largely agreeing with what people expect). Examples include talking trees and noncorporeal agents. Pascal Boyer argues that many religious entities fit into this category. Upal labelled the fact that minimally counterintuitive ideas are better remembered than intuitive and maximally counterintuitive ideas as the minimal counterintuitiveness effect or the MCI-effect. Hyperactive agency detection device Cognitive scientist Justin L. Barrett postulates that this mental mechanism, whose function is to identify the activity of agents, may contribute to belief in the presence of the supernatural. Given the relative costs of failing to spot an agent, the mechanism is said to be hyperactive, producing a large number of false positive errors. Stewart E. Guthrie and others have claimed these errors can explain the appearance of supernatural concepts. Pro-social adaptation According to the prosocial adaptation account of religion, religious beliefs and practices should be understood as having the function of eliciting adaptive prosocial behaviour and avoiding the free rider problem. Within the cognitive science of religion this approach is primarily pursued by Richard Sosis. David Sloan Wilson is another major proponent of this approach and interprets religion as a group-level adaptation, but his work is generally seen as falling outside the cognitive science of religion. Costly signaling Practices that, due to their inherent cost, can be relied upon to provide an honest signal regarding the intentions of the agent. Richard Sosis has suggested that religious practices can be explained as costly signals of the willingness to cooperate. A similar line of argument has been pursued by Lyle Steadman and Craig Palmer. Alternatively, D. Jason Slone has argued that religiosity may be a costly signal used as a mating strategy insofar as religiosity serves as a proxy for "family values". Dual inheritance In the context of cognitive science of religion, dual inheritance theory can be understood as attempting to combine the cognitive byproduct and prosocial adaptation accounts using the theoretical approach developed by Robert Boyd and Peter Richerson, among others. The basic view is that while belief in supernatural entities is a cognitive byproduct, cultural traditions have recruited such beliefs to