 The importance of the issue to the evolutionary psychologists has led to a series of arguments traded between the human behavioral ecologists and evolutionary psychologists for preferring behavior over psychology and vice versa. Two main arguments have been raised in favor of considering behavior the proper target of explanation, both from. The first is purely practical: behavior is relatively straightforwardly observable whereas psychological mechanisms are not, to the extent that the nature of only a few psychological mechanisms has been uncontroversially demonstrated (one of the few examples might be the mechanisms for learning language) (Alexander, 1990). The second is that only behavior can be an adaptation because only behavior is the actual causal nexus between the organism and its environment (Alexander, 1990; see the same idea in early form in Skinner, 1984).