A study by University of New Mexico psychologists has found that psychopaths can differentiate between right and wrong, but they fail to weigh the difference when making decisions. The findings were recently published in Psychological Science, a highly regarded national research journal in psychology.

To reach the conclusion, UNM researchers Elsa Ermer and Kent Kiehl surveyed 67 prison inmates. Although 1 percent of the population is classified as psychopathic, 20 percent of prison inmates fit the characterization.

Ermer and Kiehl tested logical reasoning to find that psychopaths struggle to understand the social contracts and personal risks that influence decisions on how to behave.

Average people who were tested understood the expected behavior when someone said, "If you borrow my car, then you have to refuel it." Psychopathic subjects, however, failed to connect that borrowing the car required action or compensation in response.

Psychopaths also demonstrated an inability to connect potential negative outcomes with risky situations, such as "If you work with tuberculosis patients, then you must wear a surgical mask."

When (UNM research) appears in a really good journal, then we get very important recognition because it's obviously more difficult to get articles published in the top journals," Smith said. "That is a reflection not only on the researcher, but the environment. UNM is seen as an environment that supports good research.