Strain theory, which is largely derived from the work of Robert K. Merton in the 1930s and 1940s, argues that social structures within society which lead to inequality and deprivation in segments of its population indirectly encourage those segments to commit crime. According to strain theory, differences in crime rates between races are the result of real differences in behavior, but to be understood as an attempt to alleviate either absolute or relative deprivation and adapt to the existing opportunity structure.