isagree about its roots and the ways and causes of its expression; the Columbine case does not support any specific theory, instead offering additional data to the discussion. Social psychology's theories of aggression fall into two basic categories: theories which suggest that aggression's roots are internal, or come from within the individual, and theories which argue that external forces work to encourage aggressive acts.
Internal theories include arguments for instinct and for biology, both suggesting that aggression is innate. As Stephen Worchel and his colleagues (1991) point out, however, "Even if we accept the view that biological mechanisms play a role in instigating violence, we must explain what triggers those mechanisms" (p. 296). Harris and Klebold were made of the same biological stuff as the classmates they shot and the parents they left heartbroken and mystified. Biology alone cannot account for their actions.
Theorists looking for triggers propose a series of possibilities. The first of these is frustration-aggression theory, which argues that the interference with and thwarting of desires results in aggressive behavior: "The greater the frustration, the greater the resulting aggression" (Worchel, 1991, p. 297). Harris and Klebold were certainly frustrated, though perhaps not more so than most adolescents. Neither had proved to be much an athlete, and their stated hatred of "jocks" could be seen as a frustration at wanting to be more physically skilled and therefore more popular in school.
Denis Boyles (1999, November) argues that antagonism toward athletes can be seen as jealousy: "Everybody's a jock in his own game. Everybody wants to come out on top" (p. 137). The hatred that Harris and Klebold expressed publicly toward athletes may have been a form of wanting to be more athletic themselves, and such frustration could be part of what led them to their violent spree. As Worchel and his colleagu...