Sociobiology (also known as Evolutionary psychology refers to a biological approach to understanding behavior which assumes that recurring patterns of behavior in animals ultimately stem from evolutionary pressures that increase the likelihood of adaptive social actions and extinguish nonadaptive practices.
Other /More definition:
Sociobiology refers to the application of evolutionary theory to social behavior; a paradigm based in the view that social behavior can be explained in terms of genetic characteristics and behavior.
Sociobiology refers to the discipline founded by Edward Wilson that attempts to explain complex social behavior in terms of evolutionary theory.
Sociobiology is also called Evolutionary psychology.