The Female Brain

In order for a female body to orgasm, the amygdala must be deactivated, Brizendine suggests, which is why female bodies, on average, take longer to reach orgasm as compared to male ones. Marcie sought Brizendine’s help when she could not reach orgasm with her current partner, John, with whom she still felt tense. While taking prescribed muscle relaxers, she was able to climax with John. The anecdote aligns with a study that found female humans must be comfortable and have warm feet before they want to engage in sex. Brizendine relates numerous studies on the female orgasm to a hypothetical description of a sexual encounter between Marcie and John: As Marcie engaged in sexual activity, “certain brain areas would become more calm,” and Marcie’s “brain area for worry and fear—the amygdala—would deactivate into a calm blue” (114). Male bodies, Brizendine asserts, are simpler and only need an erection to achieve an orgasm. Given the gender bias in medical science, far less is understood about female sexual arousal and orgasm. Despite attempts, scientists have not found a female version of Viagra. Researchers have also learned more about the anatomy of female genitalia and have discovered, contrary to Freud’s assumptions, that there are not separate vaginal and clitoral orgasms.

The female amygdala can be triggered by minor disturbances or memories, making female orgasm difficult. Julie, a patient, could not have an orgasm, and sex made her anxious. Brizendine traced Julie’s sexual dysfunction to the molestation she had experienced as a child. After undergoing trauma and sex therapies, Julie was able to reach orgasm. Multitasking also makes sexual fulfillment difficult. Brizendine suggests female partners need to be in the right mood to enjoy sexual activity and require 24 hours of foreplay. While some researchers have argued that the female orgasm serves no purpose, Brizendine believes that it has important reproductive functions—encouraging female humans to participate in sex and making it more likely that they will remain lying down after intercourse, which increases sperm retention. Orgasm also may strengthen the relationship between partners. Evolutionary psychologists have proposed that the female orgasm allows some control over fertilization, since the accompanying muscle contractions pull sperm through the cervix. As such, women may select attractive men, hoping for bigger orgasms. Female barn swallows, Brizendine notes, tend to select more symmetrical males. Such results have been demonstrated in human studies, too, and researchers believe symmetry is a visual symbol of health. Another study showed that female partners of more symmetrical men experienced more orgasms. Brizendine divides men into two groups—one “for hot sex” and one for “safety, comfort, and child rearing” (121)—and argues there is rarely overlap.

What Brizendine terms “Mother Nature” drives humans to procreate through several means, including scent. Female brains can detect male pheromones, and the brain’s sensitivity to scent is impacted by the menstrual cycle. A study by John Havlicek suggested that partnered women prefer the scent of dominant men who are not their partners, leading him to conclude that women want to have relationships with nurturing partners, but want to procreate with dominant men. Brizendine links this to studies that revealed that 30% of baby birds were fathered by males that were not the mothers’ partner. Researchers have documented that around 10% of children are not genetically related to their supposed fathers. Brizendine uses this statistic to wonder if female orgasm is more likely to occur during an act of infidelity. If true, Brizendine speculates that infidelity has an evolutionary cause—women can mate with dominant men, but partner with nurturing ones. Brizendine claims that women fake orgasms with their partners more often when they are cheating or flirting with other men, which may serve to disguise their infidelity.

In both male and female humans, sexual behavior is triggered by testosterone. Studies have shown testosterone causes flirtatious behavior in rats, and another study showed that testosterone correlated to increased sexual thoughts and masturbation in female teenagers. Male humans release more testosterone, giving them a higher sex drive. Female testosterone levels vary and are influenced by the menstrual cycle, perimenopause, and menopause. One perimenopausal patient, Jill, experienced low sex drive and was prescribed testosterone. She accidentally took double doses and experienced an extremely high libido before dropping to the correct and satisfactory dose. Progesterone lowers libido and had been prescribed for some male sex offenders. While estrogen is correlated with a higher libido, it is not the cause. Brizendine declares that women have sexual thoughts one to four times a day, while men have sexual thoughts throughout the day. This results in them coercing women into sex. The increased size of the areas correlated with sex in male brains first develops during their prenatal exposure to testosterone and is further impacted by puberty. Jane and Evan demonstrate the difference in male and female libido. As Jane’s libido dropped after beginning a stressful new job, Evan became dissatisfied with their sex life, and they sought couples therapy. Brizendine felt their problems stemmed from their different neurological perspectives. The lack of sexual intimacy made Evan feel unloved, similar to how a lack of verbal communication would make a female partner feel unloved, Brizendine asserts. The couple considered each other’s perspectives, their physical intimacy increased, and Jane got pregnant.

Motherhood alters the female brain, ensuring mothering capabilities. Syrian hamsters, for instance, ignore or eat the pups of others but care for their own. Human males and adoptive parents also experience neurological changes when in close contact with an infant. Brizendine posits that modern women who work outside the home experience profound conflicts. For example, before experiencing motherhood, Nicole was career-oriented; she attended prestigious universities then became a busy investment banker. She met and married Charlie and was forced to divide her mental energy between work and her relationship. Brizendine argues that female humans may experience a strong urge to have a child after exposure to infants. She herself felt this urge after meeting her niece.

Nicole got pregnant. Brizendine uses Nicole as an example to describe the effects of pregnancy. Hormonal changes begin two weeks after conception, when the fetus connects to the mother’s blood supply. Changing hormones may cause tender breasts, sleepiness, scent sensitivity, and increased hunger and thirst; such symptoms generally subside after four months, when the body acclimates to the hormonal shift. Brain changes Brizendine terms “love circuits” begin to develop in month five, when pregnant people first feel their fetus move. Typically, fathers hope for a male baby and mothers hope for a female one. Pregnancy may come with odd cravings and sedateness; cortisol levels increase, but result in increased vigilance rather than stress. Many women also feel distracted. The female brain slightly shrinks during pregnancy and returns to its usual size about six months after giving birth. Brizendine hypothesizes Nicole would become preoccupied with thoughts of her baby and labor, while Charlie would focus on the physical environment, such as obtaining nursery supplies. Oxytocin is released during labor, which results in rapid neurological changes. Mother sheep, for instance, must imprint their infant’s scent within five minutes post-birth, or they’ll reject their offspring. Similarly, the scent and sounds of a newborn will imprint on the female brain, allowing a mother to recognize her infant.

Mothers experience increased aggression and protectiveness. Ellie, a patient and new mother, sought help for anxiety over her husband’s income; although it had not changed, she feared it was not enough to support her and her infant. She was angry with her husband for not making more money. Other potential behavioral changes include increased flexibility, courage, and spatial memory. Mother rats have been shown to perform better in mazes and in hunting, for instance. Fathers also experience neurological alterations. Jason, an expectant father, experienced morning sickness alongside his pregnant wife and was diagnosed with Couvade Syndrome, commonly known as sympathetic pregnancy. Studies have found that prolactin increases in soon-to-be fathers and that their testosterone drops after they become fathers. Low testosterone is correlated with more responsiveness to the cries of infants.

The mother-child bond may be delayed, such as Brizendine experienced as a result of her C-section. Mother love resembles romantic love, and studies have shown both use similar neural pathways. Female brains experience releases of dopamine and oxytocin when looking at loved ones. The mother-child bond is further strengthened by breastfeeding, which also releases high levels of oxytocin and dopamine. While breastfeeding is often initially difficult, it becomes pleasurable for many nursing. Mothers may experience lower libido while tending their infant, as occurred with Lisa, another patient, who became frustrated with her husband’s needs for physical affection. Lisa’s needs for physical affection were being met while caring for her children. Breastfeeding may also result in lower mental focus. Kathy experienced memory difficulties, such as forgetting to pick up her son from school, which Brizendine attributed to her breastfeeding her infant. A mother’s brain devotes significant energy to caring for and protecting an infant, further impacting focus. Despite the side effects, Brizendine argues breastfeeding is beneficial and supports the mother-child bond. Nursing mothers may experience increased anxiety or withdrawal when separated from or weaning their infants. For mothers who return to work, such withdrawal symptoms can be mitigated by pumping breast milk.

Veronica, a pregnant patient, was anxious she might adopt her mother’s neglectful parenting style. Brizendine validates such anxiety: Research has found that busy, unattached mothers can negatively influence their child’s sense of security, and that female humans often “inherit” parenting methods. Behaviors can be passed epigenetically, as in Meany’s research, which found that rat pups’ brains changed depending on their mother’s level of nurturing. Without intervention, neglectful mothering was passed down through three generations of rats. Other studies have shown that mothering styles are similarly passed down through generations of humans. Some scientists speculate that the stress of balancing workplace and household responsibilities impacts the quality and quantity of nurturing mothers supply to their children. High levels of nurturing are associated with children’s intelligence, health, and stress management, while low nurturing is correlated with stress, hyperreactivity, sickness, and inattentiveness later in life. Veronica discussed her positive relationship with her paternal grandmother. Nurturing from substitute mother figures, or allomothers, can counteract the impacts of busy, stressed mothers. Brizendine speculates that the nurturing Veronica received from her grandmother broke the generational inheritance and helped Veronica become a nurturing mother to her daughter.

Nicole had a meltdown at the idea of returning to work. Mothers, Brizendine says, often experience conflicting responsibilities, which generates anxiety and stress. A few years later, Nicole was dissatisfied with her life. Her son has intense public tantrums and Nicole felt overworked, but could not afford to quit. Brizendine describes human and non-human collective child-rearing practices, suggesting many species balance parenting and non-parenting work. Such species rely on other members of the group to provide childcare, showing that mothers are not meant to raise children alone. Nicole was granted a more flexible work schedule and developed a symbiotic relationship with a neighboring mother where they provided childcare for each other. Predictability is also an important factor in good mothering. In one study, rhesus monkeys were divided into three categories: predictably ample food, predictably scarce food, and unpredictable food. Mothers in the first two groups displayed more nurturing, while mothers in the third became abusive. Brizendine stresses the neurological changes in motherhood and suggests that inherent female skills, such as interpreting tones or facial expressions, are important for mothering. She declares that by studying female-male neurological differences, male and female parents can better create a supportive family environment.