Theft can be motivated by need. But for kleptomaniacs, stealing can be motivated by the sheer thrill of it. One study of 43,000 people found 11 percent admitted to having shoplifted at least once.
"These are people who steal even though they can easily afford not to," says Jon E. Grant of the University of Minnesota School of Medicine.
In a study in 2009, participants either took a placebo or the drug naltrexone — known to curb addictive tendencies toward alcohol, drugs and gambling. Naltrexone blocks the effects of substances called endogenous opiates that the researchers suspect are released during stealing and which trigger the sense of pleasure in the brain.
The drug reduced the urges to steal and stealing behavior, Grant and colleagues wrote in the journal Biological Psychiatry.
Theft may be in our genes. After all, even monkeys do it. Capuchin monkeys use predator alarm calls to warn fellow monkeys to scatter and avoid threats. But some will make fake calls, and then steal food left by those that scattered.