Edwin Sutherland proposed differential association theory in 1947, which argues that criminal behavior is learned through intimate personal groups and defines criminal behavior as a learning process that can affect anyone. The theory states that individuals learn criminal techniques, motives, rationalizations and attitudes from these groups. It also acknowledges that the direction of one's motives is learned from how legal codes are defined by these groups as favorable or unfavorable. Critics argue that it does not fully explain acts of deviance that are not learned or spontaneous, or account for biological and psychological factors. However, Sutherland recognized it did not provide a complete explanation on its own and that personality also plays a role.