One of the key functions of social theory is to provide a "framework' for undertaking empirical social research (Taylor 1967). It does this by equipping the researcher with a vocabulary for describing social phenomena, together with a related set of assumptions about how to go about explaining them. Amongst these assumptions will be views about the fundamental goals and purposes that human beings strive to realize through their actions. These goals and purposes might be consciously and deliberately aimed at by individuals or groups, or they might operate behind their backs, as it were, through some sub- or supra-personal mechanism: the reproductive strategy of a gene, the striving for satisfaction of an instinct, a system's tendency towards equilibrium, and so forth. To give an example, research into the rise of teenage pregnancies will typically be "framed' by a set of assumptions about the salient motivations capable of explaining the behaviour, such as conformity to increasingly sexualized self-images, or the perception of economic benefit. To give another example, researchers investigating changing levels and types of incarceration typically have to rely on assumptions about the overarching purposes served by these practices — such as the exercise of power over life, or the maximization of utility under conditions of heightened risk — and to that extent are dependent on a theoretical framework.