ABSTRACT
Behaviors have been called “biological” to imply that they are unlearned and innately based on genetic information. Comparative anatomists have approached the problem from another direction, concentrating on species alive today. They can usually take the living species of any order of animals and, beginning with one species as a reference point, arrange the others as being more or less similar to it along such diverse criteria as gross morphology, development of the nervous system, and structure of protein molecules. Evolutionary explanations in sociology are usually not capable of direct empirical test; their acceptance depends on arguments and indirect data which make the explanations more or less plausible. Biological explanation has taken some trivial forms in sociology. At least three forms of explanation common in biology have meaningful homologues in sociology, but each has its faults. These are evolutionary explanation, genetic explanation, and neurophysiological explanation.
