Sociobiology is a field of biology that aims to explain social behavior in terms of evolution. It draws from disciplines including psychology, ethology, anthropology, evolution, zoology, archaeology, and population genetics. Within the study of human societies, sociobiology is closely allied to evolutionary anthropology, human behavioral ecology, evolutionary psychology, and sociology.

Sociobiology investigates social behaviors such as mating patterns, territorial fights, pack hunting, and the hive society of social insects. It argues that just as selection pressure led to animals evolving useful ways of interacting with the natural environment, so also it led to the genetic evolution of advantageous social behavior.

While the term "sociobiology" originated at least as early as the 1940s; the concept did not gain major recognition until the publication of E. O. Wilson's book Sociobiology: The New Synthesis in 1975. The field quickly became the subject of scientific controversy. Critics, led by Richard Lewontin and Stephen Jay Gould, argued that genes played a role in human behavior, but that traits such as aggressiveness could be explained by social environment rather than by biology. Sociobiologists responded by pointing to the complex relationship between nature and nurture. Among sociobiologists, the controversy between laying weight to different levels of selection was settled between D.S. Wilson and E.O. Wilson in 2007.

E. O. Wilson defined sociobiology as "the extension of population biology and evolutionary theory to social organization".

Sociobiology is based on the premise that some behaviors (social and individual) are at least partly inherited and can be affected by natural selection.

The discipline seeks to explain behavior as a product of natural selection. Behavior is therefore seen as an effort to preserve one's genes in the population. Inherent in sociobiological reasoning is the idea that certain genes or gene combinations that influence particular behavioral traits can be inherited from generation to generation.

For example, newly dominant male lions often kill cubs in the pride that they did not sire. This behavior is adaptive because killing the cubs eliminates competition for their own offspring and causes the nursing females to come into heat faster, thus allowing more of his genes to enter into the population. Sociobiologists would view this instinctual cub-killing behavior as being inherited through the genes of successfully reproducing male lions, whereas non-killing behavior may have died out as those lions were less successful in reproducing.

The philosopher of biology Daniel Dennett suggested that the political philosopher Thomas Hobbes was the first proto-sociobiologist, arguing that in his 1651 book Leviathan Hobbes had explained the origins of morals in human society from an amoral sociobiological perspective.