At an instinctual and non conscious level, man's thoughts, choices and actions are motivated by his goals. The primary motive is self regarding and is the "want" to pursue pleasure or avoid pain. These goals (values and detriments), may be extrinsic or intrinsic. While any given thought, choice or action may have an ulterior other regarding motive, there is no pure altruism.
Affective Egoism is distinct from a system of ethics which prescribes the right course of action for how man ought to pursue his goals. An example of a prescriptive conscious egoism is Ayn Rand's Rational Egoism.