A 2006 experiment about "justice served" suggests that men, but not women, enjoy seeing "bad people" suffer. The study was designed to measure empathy by watching which brain centers are stimulated when subjects observed via fMRI see someone experiencing physical pain. Researchers expected that the brain's empathy center of subjects would show more stimulation when those seen as "good" got an electric shock, than would occur if the shock was given to someone the subject had reason to consider "bad". This was indeed the case, but for male subjects, the brain's pleasure centers also lit up when someone got a shock that the male thought was "well-deserved".