The study, published in the September-October issue of Psychosomatic Medicine, measured testosterone in 87 female inmates at a maximum security prison. Their criminal behavior was scored from court records, and their prison behavior was assessed from prison records and staff interviews.

Testosterone was found related both to the violence of the women's crimes and to the aggressive dominance of their behavior in prison. This finding was further supported by assessing how an inmate's age corresponded to her behavior and testosterone levels.

As the amount of the hormone measured decreased in older prisoners -- testosterone declines with age -- so did the aggressive dominance. But the study concluded that testosterone, not age alone, was the significant factor; older inmates who had high hormone levels were not less aggressive or dominant.

"The key to this study is it shows testosterone is linked to dominance in both criminal behavior and behavior in prison," says Dr. James Dabbs, a professor of psychology at Georgia State University and lead researcher on the project.

The findings, by Dabbs and Marian Hargrove, are similar to those in studies of male prisoners. This indicates testosterone's effects on behavior are the same in women as in men, says Dabbs. Testosterone levels were highest among male inmates convicted of violent crimes such as rape, homicide and assault. These men also violated more prison rules.

An intriguing observation from the study on women was discovered when prison staff members were asked to describe the five inmates who were lowest in testosterone. The three staff members used phrases like "very manipulative" and "sneaky," but all agreed the word "treacherous" best described the women.

This doesn't mean having low testosterone is trouble, says Dabbs. But in a specific population, such as prisoners, this type of negative, underhanded behavior might be expected from those who lack other elements of power such as the aggressive dominance seen in those with high testosterone, he says.

The study's findings indicate testosterone plays an important role in the female criminal population, but variables such as age, social factors, and other hormones must also be considered, says Dabbs.

The study was supported by grants from the National Institute of Mental Health and the National Science Foundation.

Note: If no author is given, the source is cited instead.

• Men's Health
• Prostate Health
• Prostate Cancer

• Behavior
• Gender Difference
• Social Psychology

• Prison
• Hormone replacement therapy
• Testosterone
• Service dog
• Endocrine system
• Androgen