has been linked to oxytocin, for example.
Girls flock together and keep social harmony, often through language. Staying connected via gossip and verbal intimacy leads to a rush of dopamine, one of the brain’s pleasure chemicals, and oxytocin. Estrogen triggers dopamine and oxytocin production in pubescent girls. Midcycle, these hormones peak, as do verbal output and desire for intimacy. Whereas women tend to discuss troublesome issues with peers, men tend to process their troubles alone, nonverbally. This may reflect the balance of oxytocin versus testosterone. Testosterone inhibits talking and the drive to socialize. For boys, self-esteem comes from being independent, not interconnected. Boys aren’t as communicative, and they aren’t nearly as derailed by conflict and competition. It’s part of who they are, and, perhaps equally important, who they’re expected to be.
The connections between the areas of the brain that process emotion are more active and extensive in women. Women have nine areas devoted to this function, compared with only two in men. Women also have more bilateral processing of emotions in their brains, going left to right, right to left, connecting the analytic and emotional areas, whereas men tend to stay more within each hemisphere. So we could say that women are using their whole brains while men are often using only half of theirs at a time. Women do seem to be better at multitasking than men. Men not only have more difficulty juggling multiple priorities but they are also slower and less organized than women when switching between them.
Men’s brains have more linkages with their cerebellum, the control center for movement, so for men, there may be less time between seeing and doing than there is for women. Men tend to outperform women on motor and spatial cognitive tasks, while women are faster in tasks of emotional identification and nonverbal reasoning. We also outperform men on a “lost key” challenge; maybe this is why our families ask us where everything is, and, more important, why we know the answer. Because men were primarily the hunters and we the foragers, it was crucial that we remembered where we last found the good food.
Obviously, we must be cautious in discussing differences between the sexes because there is a large variation within each gender, and nurture and culture factor in nearly as much as nature does. There is interplay between our natural abilities and how we are molded to behave that is impossible to fully tease apart. Case studies of children with ambiguous genitalia who are raised to be male or female even though they possess the opposite genetic material are rare, but they do help to teach us one thing: the influence of biology cannot be underestimated. Often, our own balance of testosterone and estrogen levels dictates how aggressive we’ll be in a pickup game of basketball (or if we’d ever be caught dead in a pickup game of basketball) more than anything our parents ever taught us.
The Downside to Feeling Deeply
While biology may provide women with a set of attributes, from brain structures to hormones, that are advantageous in our traditional roles of nurturing and caregiving, there is a downside. These same attributes may also make us more inclined to suffer from depression and anxiety. In childhood, no difference exists in the prevalence of depressive disorders between girls and boys. In adulthood, women are twice as likely as men to experience depression and two to four times more likely to be diagnosed with an anxiety disorder like panic attacks or generalized anxiety.
The increased risk begins early in adolescence as puberty strikes. It ends by age sixty, when hormonal cycling ceases. Although some of the increased incidence of depression in women may result from societal factors like body image pressures, or their greater tendency to seek help for mental health issues, or diagnostic bias among doctors, there is strong evidence that much of the gender difference in mood disorders is linked to hormones.
Some women are more susceptible to hormonal fluctuations than others. There is a subgroup of women who seem to be at risk for what’s called reproductive depression, that is, mood changes caused by variations in hormone levels, like those seen prior to menstruation or after delivery. If you’re the PMS type, you’re also more likely to have postpartum depression or perimenopausal mood instability. Certain women have a specific sensitivity to these hormonal changes while some lucky ones don’t, possibly dictated by genes governed by changing estrogen levels. The good news is, when your hormones aren’t fluctuating, like when you’re postmenopausal, the risk for depression isn’t elevated. After menopause, the risks even out, especially two years after the final menstrual period, when the dust has settled. There is truth to the idea that the years after menopause are a real prime time of life for many women, both professionally and personally.
Again, there are likely evolutionary reasons for mood variability being tied to hormonal fluctuations. There is a positive mood state (called euthymia) in the first half of the menstrual cycle, leading up to ovulation, that encourages a woman to connect with mates and conceive. The more depressed, progesterone-heavy state in the second half of the cycle helps to ensure the safety of the product of conception by keeping the woman passive, cautious, and out of danger. Progesterone rises during the second half of the menstrual cycle and surges even higher if an egg is fertilized. It is the main hormone that maintains pregnancy. Progesterone is implicated in premenstrual syndrome, postpartum depression, and dysthymia, a chronic low-grade depression. The increased incidences of depression and anxiety during pregnancy (particularly in the first trimester) and the immediate postpartum period come during crucial periods for the baby, when more cautious and isolative maternal behavior can help ensure the baby’s survival. If women develop these behaviors, whether conserving precious energy or avoiding dangerous situations, then these traits will be passed on. Viva Darwin.
Anxious and depressed behaviors have survived in our gene pool for millennia because they are adaptive. They confer an advantage to our survival and that of our offspring. An anxious, obsessive forager will not only find more food, but will also return home safely. She is also more likely to keep her children out of harm’s way. Likewise, a depressed woman will more quickly withdraw from wasted enterprises, whether pursuing food or a mate, and conserve her energy. This may be the basis for seasonal affective disorder, which causes lower energy and motivation when food supplies are most scarce.
When women feel under threat, estrogen helps us to “maintain,” to be resilient and bounce back. In this way, estrogen is really acting as a stress hormone. One of the ways estrogen builds resilience is by enhancing serotonin levels, which help to keep us fortified, calmer, more rational, and less emotional. Serotonin activity is greater during higher estrogen levels. When estrogen surges, it causes more serotonin to be made, and it also causes
