Popular perceptions of the effect of testosterone on "manly" behavior are inaccurate. We need to move away from such simplistic notions by treating testosterone as one component along with other physiological, psychological and sociological variables in interactive and reciprocal models of behavior. Several hormones can now be measured in saliva, removing the need for blood samples. Conceptual shifts have moved research from biological determinism to biosocial models in which the social environment plays a key role in understanding behavior-hormones associations. As a result, more social scientists are incorporating testosterone in their studies. Following a primer on testosterone, we describe testosterone's link to (a) gaining, maintaining and losing social status, (b) aggression and antisocial behavior, (c) peer and family relationships, and (d) gender similarities and differences. Research needed to take us to the next level of understanding is outlined. (Contains 3 figures.)