Agnew’s General Theory of Strain, in my opinion, best explains Tommy Shakur’s decision to join a gang. A theory is the general strain theory. Agnew’s General Theory of Strain, in my opinion, best explains Tommy Shakur’s decision to join a gang. Robert Agnew developed a theory known as the general strain theory. It claims that strained emotions like depression, frustration, and anger lead to violence, especially violent crime. According to the differential association theory, criminal behavior is acquired through social interaction. He observed something among the other gang members that led him to believe that gang life was truly remarkable.