SEEING THE WORLD THROUGH MALE-COLORED GLASSES

If a woman could see the world through "male-colored glasses," she'd be astonished by how different her outlook would be. When a boy enters puberty and his body and voice change, his facial expressions also change, and so does the way he perceives other people's facial expressions. Blame it on his hormones. A key purpose of a hormone is to prime new behaviors by modifying our brain's perceptions. It's testosterone and vasopressin that alter a teen boy's sense of reality. In a similar fashion, estrogen and oxytocin change the way teen girls perceive reality. The girls' hormonally driven changes in perception prime their brains for emotional connections and relationships, while the boys' hormones prime them for aggressive and territorial behaviors. As he reaches manhood, these behaviors will aid him in defending and aggressively protecting his loved ones. But first, he will need to learn how to control these innate impulses.

Over the past year, for no good reason, Jake began to feel much more irritable and angry. He would quickly jump to the conclusion that people he encountered were being hostile toward him. We might ask, Why did it seem the whole world suddenly turned on him? Unbeknownst to Jake, vasopressin was hormonally driving his brain to see the neutral faces of others as unfriendly. Researchers in Maine tested teens' perceptions of neutral faces by giving them a squirt of vasopressin nasal spray. They found that, under the influence of this hormone, the teen girls rated neutral faces as more friendly, but the boys rated the neutral faces as more unfriendly or even hostile. This may explain why the next time Jake saw Dylan, he thought his face looked angry when, in fact, Dylan was just bored. Jake's brain was being primed by hormones for getting into trouble.

In animals that are in puberty, scientists have discovered that priming the males' brains with vasopressin and testosterone changes their behavior, too. The scientists found that the brain's two master sensors for emotions--the amygdala and hypothalamus--became supersensitive to potential threats when hormonally primed. And in animal studies in which male voles were given vasopressin, it resulted in more territorial aggression and mate protection.

In humans, a potential threat is often signaled by a facial expression. Before puberty, when Jake had less testosterone and vasopressin, Dylan's bored face probably wouldn't have looked hostile or angry to him. But now everything was different. Evolutionary biologists believe seeing faces as angrier than they actually are serves an adaptive purpose for males. It allows them to quickly assess whether to fight or to run. At the same time, Jake and Dylan were also honing the ancient male survival skills of facial posturing and bluffing. They were learning to hide their emotions. Some scientists believe human males have retained beards and facial hair, even in warmer climates, in order to make them look fierce and hide their true emotions.

In the male hierarchy of primates and humans, the angry face is used to maintain power. And the angriest faces typically belong to men with the highest testosterone, according to research. A study of teen boys in Sweden found that the ones with the most testosterone reacted more aggressively to threats. These boys with the highest testosterone also reported being more irritable and impatient. And in another study, testosterone levels rose in response to seeing an angry face, thus dialing up the brain circuits for aggression. So angry faces--real or imagined--ignite the male fighting spirit. As Jake and Dylan had experienced in their shoving match, this sudden anger can trigger a knee-jerk reaction--often surprising even to the fighters. If these two boys had lower testosterone and vasopressin, they would not have been so fired up to fight and wouldn't have felt compelled to even the score. But as it was, this hormone cocktail was keeping an irritable and sometimes irrational fire smoldering.