In psychology, value theory refers to the study of the manner in which human beings develop, assert and believe in certain values, and act or fail to act on them.

Attempts are made to explain experimentally why human beings prefer or choose some things over others, how personal behaviour may be guided (or fail to be guided) by certain values and judgements, and how values emerge at different stages of human development (see e.g. the work by Lawrence Kohlberg and Kohlberg's stages of moral development).

In psychotherapy and counselling, eliciting and clarifying the values of the client can play an important role to help the client orient or reorient himself or herself in social life.