In Brief

  • Monogamy may be genetic: Men are more likely to be committed and loyal husbands when they lack a particular variant of a gene that influences brain activity, according to a study in the Proceedings of the National Academy of Science (Vol. 105, No. 37). Using data from more than 550 twins and their spouses, scientists at Karolinska Institute in Stockholm found that men with two copies of allele 334 were more than twice as likely to report serious marital or relationship problems than men who did not carry it. In addition, women married to men with one or two copies of the gene were, on average, less satisfied with their relationships than those married to men who lacked the gene.

  • People spend less when they pay with cash rather than with a credit card or gift certificate, concludes a study examining buying habits in the September Journal of Experimental Psychology: Applied (Vol. 14, No. 3). Consumer behavior experts Priya Raghubir, PhD, and Joydeep Srivastava, PhD, say this may be because the pain of paying is dulled by less transparent payment modes. "Forms of payment other than cash tend to be treated like 'Monopoly' money, and that leads to overspending," says Raghubir.

  • Older problem casino gamblers may face greater suicide risk than their younger counterparts, researchers say. A study in the September Psychology and Aging (Vol. 23, No. 3) finds that adults over age 55 who ask casinos to bar them from returning are three to four times more likely to do so because they fear they will kill themselves if they don't stop betting. Study author Lia Nower, JD, PhD, from the Rutgers University Center for Gambling Studies, says the results highlight the need for more research and services targeted to older adults who gamble at casinos.

  • Intellectual work induces us to eat more, according to an article in the September Psychosomatic Medicine (Vol. 70, No. 7). Students at Laval University in Quebec City, Canada, consumed as much as they wanted from a buffet after each of three tasks: relaxing in a sitting position; reading and summarizing a text; and completing a series of memory, attention and vigilance tests on a computer. Despite the low physical energy expended during the mental work, the students consumed 24 percent more calories after summarizing a text and 29 percent more calories after the computer tests. These findings may provide insight into the rising obesity epidemic among industrialized nations, researchers say.

  • Having traditional attitudes toward gender helps men's pay, according to a study in the September Journal of Applied Psychology (Vol. 93, No. 5). Using data from a nationally representative survey of more than 12,000 men and women, researchers Timothy Judge, PhD, and Beth Livingston, of the University of Florida, found that men who believe in traditional roles for women make more money than men who don't. For women, having traditional gender attitudes hurts their earnings, but to a smaller degree. The researchers found that these differences remained even after controlling for hours worked, occupation and number of children. "The gender wage gap may be as much a psychological phenomenon as an economic one," says Judge.

  • A study in the September issue of Brain (Vol. 131, No. 9) reports that bedwetting occurs twice as often in children who grow up to have schizophrenia than in their unaffected siblings or normal controls. Investigators also found that those schizophrenia patients with a history of bedwetting showed reduced gray matter in the front of the brain—the area associated with bladder control—indicating that abnormalities in brain maturation may be a precursor to the disorder, notes lead author Thomas M. Hyde, MD, PhD, of NIMH.

—A. Novotney