Testosterone, crime, and prison behavior were examined among 692 adult
male prison inmates. Testosterone was measured from saliva samples, a
nd behavior was coded from prison system records. Inmates who had comm
itted personal crimes of sex and violence had higher testosterone leve
ls than inmates who had committed property crimes of burglary, theft,
and drugs. Inmates with higher testosterone levels also violated more
rules in prison, especially rules involving overt confrontation. The f
indings indicate differences between low and high testosterone individ
uals in the amount and pattern of their misbehavior.