 Unlike ethologists, behavioral ecologists studying animal behavior at first tended to focus on the third question, the question of evolutionary function, at the expense of the others (Griffiths, 2008; Krebs and Davies, 1997). Griffiths (2008) has argued such a focus by the behavioral ecologists on questions of function at the expense of questions of causation, development and phylogeny (but especially development) was highly problematic, since the four questions cannot be properly answered independently. Development constrains the evolution of biological traits in multiple ways, and behavior especially, since behavior depends on development at both neurological and psychological levels. Behavioral ecologists, however, for a long time took the complexity of the developmental resources contributing to behavior as a reason for (at least temporarily) avoiding such studies as part of their study of the evolution of behavior. Grafen (1984) argues that the problem with developmental approaches to behavior is that they are hard and lengthy to perform, especially if the only or primary purpose of the developmental work is to check that the trait in question does indeed have an evolutionary history that can be understood using adaptationist methods. Grafen argues that if behavioral ecologists had to perform developmental or psychological studies to be relatively confident of their conclusions about the evolutionary history of traits, they would probably never get as far as evolutionary studies, since such developmental and genetic work would take a very long time. Worse, such studies might well have no inherent interest of their own and represent a waste of time and resources for the scientist—not all traits have an interesting or enlightening developmental background or are produced by interesting and unknown psychological mechanisms. Instead, Grafen argues that behavioral ecologists should use what he calls the “phenotypic gambit” in studying the evolution of behavioral traits. This involves assuming that the developmental, psychological and genetic proximate causes of a behavioral trait, such as the jewel wasp’s egg-laying strategy are of a type that will permit scientists to “pretend” that they are very straightforward when building evolutionary models, and yet still end up with models that give approximately the right answers about the primary processes, conditions and constraints acting on that trait during its evolution (for another similar view see Maynard Smith, 1982, 6ff).