There are a wide range of subcultural theories – most, but not all, from functionalist sociologists – that seek to explain why groups of young people commit crimes together. It is based on the idea that a group might have their own norms and values, distinct from the value consensus of mainstream society. These theories are influenced by Merton's strain theory and come from sociologists such as Albert Cohen (status frustration), Cloward and Ohlin (illegitimate opportunity structures) and Walter MIller (focal concerns).