:: By Lydialyle Gibson

:: Image courtesy Andrey Kravtsov

Investigations ::

That baby face
Just by looking at a man’s face, women can accurately gauge his testosterone level and his affinity for children, says Chicago behavioral biologist Dario Maestripieri. In a study coauthored with University of California, Santa Barbara, researchers, 39 ethnically diverse male students took testosterone tests, looked at baby pictures, and were photographed making neutral expressions. Based on those photos, 29 undergraduate women rated each man’s masculinity, liking for children, and appeal as a short- or long-term mate. Picking kid-friendly guys as the most marriageable, 20 women guessed right about which men indicated a strong interest in children, and 19 pinpointed those with no interest. The findings were published in the May 9 Proceedings of the Royal Society B: Biological Sciences.

Anger management
Road rage has a new name. In a report published in the June Archives of General Psychiatry, Chicago psychiatry chief Emil Coccaro suggests that one in 20 Americans may suffer from intermittent explosive disorder (IED), characterized by uncontrollable anger and unjustifiably violent outbursts. Interviewing 9,282 people 18 and older, Coccaro—the first to document IED in 2004—and colleagues at Harvard mapped abnormal brain activity in sufferers and found that 80 percent of them develop other mental problems like anxiety disorder and alcohol abuse.

Big-bang boost
Dark matter may remain invisible and unknown, but during the big bang it corralled luminous matter into a web of galaxies and galaxy clusters—and a computer simulation by Chicago astrophysicists shows how. Using telescopic observations from as far back as seven billion years, associate professor Andrey Kravtsov, research fellow Risa Wechsler, and graduate student Charlie Conroy demonstrated that hydrogen, helium, and heavier elements congregate as gas, then cool and contract until they’re dense enough for galactic-scale star formation. Reported in the June 20 Astrophysical Journal, the findings offer finer detail than ever before to support a popular big-bang scenario—without having to rely on complex assumptions.

Power naps help docs
For medical residents, a few moments of shut-eye make a difference. Assessing the benefits of napping during extended periods on call, Chicago internist and medical instructor Vineet Arora, AM’03, found that just 41 extra minutes of sleep reduce fatigue during a 30-hour shift. Instituting a nap schedule for 38 first-year residents—they averaged 185 minutes of sleep per night instead of 144—she reported in the June 2 Annals of Internal Medicine that fatigue ratings dropped. On a seven-point scale, nappers logged an overall sleepiness of 1.74 (higher means sleepier), versus 2.26 for those on a standard schedule.

When welfare-to-work doesn’t
A pioneer in the 1996 welfare-to-work reforms, Wisconsin reduced public-aid rolls by 80 percent in just a few years. Offering child care and tax credits while tightening work requirements and cash benefits, the state helped place recipients in jobs. But in a study released in May by the Chapin Hall Center for Children, SSA professor and center director Mark E. Courtney says those still on welfare are much needier—hobbled by disabilities, mental-health problems, and substance abuse—and the system often fails to help. In 1999 researchers began following 1,075 welfare applicants, chiefly black single mothers, and found that most cycled in and out of the program, working only intermittently and failing to support themselves.