Evolutionary Psychology (EP) has found itself on the forefront of modern psychological research as a result of its unique inclusive approach. This chapter provides a theoretical model of EP that is both developmental and holistic by introducing a new method of study called Dynamic Adaptive Psychology. Though EP takes an epigenetic approach, examining interactions between adapted traits and the environment, the view appears to be that of predetermined epigenesis. EP is limited in its focus because it fails to incorporate development in explanations of human behavior. From this perspective, species-specific behaviors are viewed as invariant—given trait x and experience y, the behavior will emerge. The chapter discusses the developmental systems theory (DST). From the DST perspective, behaviors develop as a result of a series of unfolding interactions between the organism and distinct objects within its environment. While the organisms are always integrated with their environment, interactions with distinct objects within their environment are constantly guided by their previous interactions.