Therese Huston in the NYT:
Researchers have shown for years that men tend to be more confident about their intelligence and judgments than women, believing that solutions they’ve generated are better than they actually are. This hubris could be tied to testosterone levels, and new research by Gideon Nave, a cognitive neuroscientist at the University of Pennsylvania, along with Amos Nadler at Western University in Ontario, reveals that high testosterone can make it harder to see the flaws in one’s reasoning.
How might heightened testosterone lead to overconfidence? One possible explanation lies in the orbitofrontal cortex, a region just behind the eyes that’s essential for self-evaluation, decision making and impulse control. The neuroscientists Pranjal Mehta at the University of Oregon and Jennifer Beer at the University of Texas, Austin, have found that people with higher levels of testosterone have less activity in their orbitofrontal cortex. Studies show that when that part of the brain is less active, people tend to be overconfident in their reasoning abilities. It’s as though the orbitofrontal cortex is your internal editor, speaking up when there’s a potential problem with your work. Boost your testosterone and your editor goes reassuringly (but misleadingly) silent.
In a classic study conducted at the University of Wisconsin, college students taking final exams rated their confidence about each answer on a five-point scale, “one for a pure guess” and “five for very certain.” Men and women both gave themselves high scores when they answered correctly. But what happened when they’d answered incorrectly? Women tended to be appropriately hesitant, but men weren’t. Most checked “Certain” or “Very certain” when they were wrong, projecting as much confidence for their bad answers as for their good ones.