When Bullfighting's in the Blood

An enzyme linked to extreme thrill-seeking.

By Peter Doskoch, published on September 01, 1994 - last reviewed on August 30, 2004

Spanish tradition dictates that a bullfighter be awarded the ears and tail of his victim after a particularly successful performance. But a more apt--and less gruesome--reward might be a lifetime supply of an enzyme called monoamine oxidase (MAO).

Bullfighters, a Spanish psychiatrist finds, are lacking in this important biochemical. And that just might explain why they've chosen such a dashing--literally and figuratively--occupation.

MAO serves as a chemical safety valve, breaking down the brain's excess supplies of neurotransmitters like dopamine and norepinephrine. It is also found in blood platelets. Low MAO levels, as measured in platelets, have been associated with a variety of psychological traits and disorders, including schizophrenia, suicidal and impulsive behavior, and sensation-seeking.

That last term certainly applies to Spain's 500 or so professional bullfighters. When Jose L. Carrasco, M.D., and his colleagues in Madrid examined platelet MAO levels in 16 bullfighters, they found that the matadors had an average of 17 percent less MAO than did police explosives experts and doctors. Three psychological questionnaires indicated that the bullfighters were also significantly more thrill-seeking and extroverted.

Carrasco, who presented his findings to the American Psychiatric Association, speculates that MAO levels might play a major role in the career choice of sensation seekers like bull-fighters.

The bullfighters' impulsiveness was apparent even without the psychological tests. When Carrasco asked them to participate in the study, most enthusiastically agreed. But they proved as adept at dodging appointments as they are at dodging toros. Often Carrasco had to go their homes for blood samples. "I had a hard time," he says.

Still, he plans to continue. He is recruiting more bullfighters and extending his analysis to monitoring levels of the brain chemicals serotonin and norepinephrine. Ole!