Vol. 5, No. 4, 1999 Page 2

Murderers offer clues about nature, nurture

Many of the most gruesome crimes are committed by people from good families and good neighborhoods. One study of 38 murderers, for instance, found that 26 of them grew up in loving families, with no abuse or neglect that could explain their crimes. Accord ding to a new study by Adrian Raine et al., brain abnormalities play a strong role in such crimes.

Raine and colleagues used PET scans to measure prefrontal cortical functioning in 41 murderers with and without histories of abuse, neglect, extreme poverty, or other types of psychosocial deprivation. All of the subjects had pled either not guilty by rea ason of insanity, or incompetent to stand trial.

The researchers report that murderers without histories of psychosocial deprivation exhibited markedly lower prefrontal glucose metabolism, particularly in the right orbitofrontal cortex, than either non-criminal control subjects or murderers with trouble ed backgrounds. In the first group, Raine et al. speculate, “the ‘social push’ to violence is minimized, and consequently, brain abnormalities provide a relatively stronger predisposition to violence.”

The researchers note that the orbitofrontal cortex is of particular interest to researchers investigating violence, because dysfunction in this brain area is linked to the types of personality and emotional deficits seen in psychopaths. Raine and colleagu ues theorize that the significant orbitofrontal deficits seen in non-deprived murderers, particularly in the right hemisphere, may cause emotional blunting and prevent the development of a normal conscience.


“Prefrontal glucose deficits in murderers lacking psychosocial deprivation,” Adrian Raine, Jacqueline Stoddard, Susan Bihrle, and Monte Buchsbaum, Neuropsychiatry, Neuropsychology, and Behavioral Neurology, Vol. 11, No. 1, 1998, pp. 1-7. Add dress: Adrian Raine, Dept. of Psychology, USC, Los Angeles, CA 90089-1061.

Return to:
[Author Directory] [Front Page] [Issue Index] [Subject Index] [Title Index]