Conservatives, it turns out, react more strongly to physical threat than liberals do. In fact, their greater concern with physical safety seems to be determined early in life: In one University of California study, the more fear a 4-year-old showed in a laboratory situation, the more conservative his or her political attitudes were found to be 20 years later. Brain imaging studies have even shown that the fear center of the brain, the amygdala, is actually larger in conservatives than in liberals. And many other laboratory studies have found that when adult liberals experienced physical threat, their political and social attitudes became more conservative (temporarily, of course). But no one had ever turned conservatives into liberals.