ABSTRACT
Establishing romantic relationships and initiating sexual activity are key developmental tasks during adolescence and early adulthood. These transitions have important emotional-affective dimensions, but they also rest on the biological changes of puberty, which eventually culminate in sexual maturity. Beyond the obvious functional implications for sexuality and reproduction, biological concepts and processes historically have been central to developmental theory and are at the core of the concept of change (e.g., Harris, 1957). Some classic biologically based theories (e.g., Freudian models) reflect predetermined epigenetic models of development in which biology is viewed as driving development, and unidirectional structural and functional development is assumed (Gottlieb, 1998). Although these models are compatible with what Petersen and Taylor (1980) labeled “direct effects” models, in which the physiological changes of puberty, for example, may directly affect adolescent interests or behavior, they are not synonymous, as “direct effects” do not necessarily imply unidirectional action.
