The Brain in Love: 12 Lessons to Enhance Your Love Life (11 page)

RULES FOR HIM, RULES FOR HER

Navigating Gender Differences in the Brain

“The genetic differences between the sexes are hundreds of times more significant than the differences between the races. You can’t look at an fMRI of someone and say, ‘That’s an African-American brain, or a Caucasian brain.’ But you can differentiate between a male and female brain.”

—STEVEN B. JOHNSON

W
hen Nicole threatened to leave Christopher, she said that their communication was like “a square peg in a round hole.” They came to see me on the advice of a friend. Christopher was completely confused during their first session. He had no idea what she meant. Nicole said that she was tired of him not listening to her, always wanting to fix her, and not being present for her when she needed him. Bewildered, Chris argued that he loved her, spent hours listening to her, and just wanted to be helpful to her. I watched in pain as this couple played out a common gender war. I had once been victim of the same drama myself. When the love relationship I discussed in the last chapter ended, the woman used the same phrase as Nicole, “square peg in a round hole.” Hearing it again, I felt a sharp pain sting my heart.

Male-female communication styles are radically different, brain-based, and hardwired. Many people think these differences are culturally defined, yet they appear very stable across almost all cultures studied and have their roots in the brain. Men and women evolved different brains over millions of years, because of necessity. Men chased down food for their families and provided protection. Women cared for the young and old, and provided a nurturing environment. Because of these different roles, the sexes evolved to process information differently, think in radically different ways, expect different things, and have different perceptions, beliefs, and behaviors. In the last forty years, as the gender roles in our society have been blurred, both males and females have become more and more confused as to what is normal behavior. We expect our partners to be able to read our minds and think as we think. Unfortunately, we are just not wired that way.

Knowing about the differences between men and women will help you be more effective in interacting with the opposite sex and help you navigate relationships without feeling hurt or rejected. In this chapter I will look at how male and female brains develop, the differences between the left and right hemispheres (which gives us clues to male-female differences), the differences in language and intuition, and the answers to commonly asked questions. I will also give males and females eight rules each for effectively dealing with each other’s brains.

Different from Conception

The moment of conception determines gender. Males get an X chromosome from the mother and a Y chromosome from the father (XY), while females get X chromosomes from both Mom and Dad (XX). Inheriting a Y chromosome triggers two bursts of hormones, mostly testosterone, that change the brain and body. The first burst early in the womb differentiates the boy’s brain from the girl’s. From early in infancy, girl brains are more interested in smiling, communicating, people, and security; while boy brains are more
interested in objects, actions, and competition. With higher levels of testosterone, the male areas of the brain are more developed, including the parietal lobes responsible for sense of direction, visualizing objects in three dimensions (good for catching a football), and mathematics. Without testosterone, the language centers of the brain are more developed, which is why girls like to talk and boys like to play catch. In addition, testosterone beefs up the area of the brain that is interested in sex. This area is twice as large in men as women. He really is more interested in sex.

The second burst of testosterone during puberty starts to turn a boy into a man. He now has twenty times the level of testosterone as most girls, his testicles descend, his voice deepens, his body becomes hairier, he has more well defined muscles, and he begins to grow like a beanstalk. His mind becomes highly focused on girls.

Since the female brain is exposed to little testosterone, her sexual development is very different. Her brain sends a message to the ovaries that it is time for the body to change. The ovaries begin to make much higher levels of estrogen and other hormones that cause the body to change in shape and size. They get the body ready for reproduction. Her breasts begin to grow, the nipples get larger and darker, curves begin to form as fat is deposited in the breasts and hips, and hip bones widen, which makes the waist look smaller. Her moods may begin to shift, she becomes much more interested in her appearance, and boys become the primary topic of discussion.

Two Minds in One Brain: Left Versus Right

The brain is divided into two sides or hemispheres, left and right, connected by three nerve fiber bundles. The largest nerve bundle is called the corpus collosum. Each hemisphere specializes in certain functions (although there is considerable overlap). We call one hemisphere dominant, usually the left side, because it is responsible for handedness and language, and the other side non-dominant, usually the right side, because it houses other functions that are not as obvious. The left hemisphere is dominant in almost
all right-handed people and about half of left-handed people. For this discussion I’ll refer to the left hemisphere as the dominant hemisphere and the right hemisphere as the nondominant.

The left hemisphere has received bad press through the years—being thought of as the uptight, materialistic, controlling, unfeeling, and unemotional side of the brain. In fact, the left hemisphere is likely responsible for human success. It is analytical, logical, precise, detail oriented, and capable of conceiving and executing plans. The left hemisphere has more gray matter, which means a greater density of nerve-cell bodies. The left hemisphere is communicative and time sensitive, breaks down complicated patterns into component parts, and is heavily involved with planning. It is the happy, cheerful, more optimistic side of the brain. When there is good activity in the left-frontal lobe, people tend to be joyful and approach their lives with a positive zest for life. When the left hemisphere is hurt, people are often depressed, negative, and irritable. Sixty percent of people who have a left-frontal lobe stroke will develop a major depression within a year. A consistent brain-imaging finding in major depression is low activity in the left-front side of the brain.

The right hemisphere sees the big picture, or gestalt of situations. It allows us to see the forest, while the left hemisphere is responsible for the trees. The right hemisphere tends to be dreamier and more artistic. It helps us recognize familiar faces and is responsible for hunches and intuition. It also sees patterns at a glance. The right hemisphere has more white matter. Its neurons are connected from farther distances, which help it to draw on several different brain regions at a time. This allows the right hemisphere to come up with broad, multifaceted but vague concepts. The right side of the brain also allows people to know when problems are present and when they should be taken seriously. Unlike the left side, when the right hemisphere is hurt, people are often unduly happy, jocular, and in denial of any problems. People with right-sided strokes may develop “anosagnosia,” failure to recognize disabling conditions. In the face of adversity, people with
right-hemisphere damage may appear unconcerned or even optimistic. The right hemisphere tends to be more negative, fearful, anxious, mournful, and pessimistic. In looking at the differences between the left and right hemispheres, it is as though there are two individuals in one skull.

There are several practical applications of left-versus-right-hemisphere research, such as where to stand in a conversation, or what side of your partner’s neck to kiss during lovemaking. Due to how our brain processes information, if you stand to someone’s right side, you are processed more prominently in the left side of his brain, the happier side of the brain. If you stand to someone’s left, you are processed more in the right side of his brain, the more anxious and negative side of the brain. Some research indicates that salespeople do significantly better when standing to someone’s right. When you ask someone to marry you, interview for a job, try to make a sale, or preach from the pulpit, stand to the audience’s right side, so that you are processed more in the happier left side of the brain; you may have a better chance of getting what you want. In a similar way, if you kiss someone on the right side of the body, she likely processes the kiss more intensely on the left side of her brain, the happier side of the brain, and she is more likely to want you to continue. If you kiss her on the left side of the neck, she processes the kiss more intensely on the right side and may feel more bugged or irritated by the kiss. Pay attention to the reactions of others, depending on where you stand and how you touch them. It may help.

Gender Brain Differences

Several of the gender differences in the brain correlate with the left-right hemisphere differences. It has been reported that men have more total brain cell numbers, even when corrected for their increased total body weight. It has been estimated that men have 4 percent more neurons than women do. When I state this fact in lectures, many women groan and complain. I then tell them about
a time when I was on the Carolyn Davidson radio show in Dallas, when she asked me, “Tell me Dr. Amen, why do men need one hundred grams more brain tissue to get the same things done as women?” It has been estimated that women have a greater number of cellular connections than men.

The corpus collosum, a large fiber band that connects the hemispheres, has been found in some studies to be larger in women, allowing greater access to both sides of the brain. Men tend to be more left sided in their approach to life, while women tend to use both sides more often then men. This is very important in helping us understand the differences between men and women. In language, men tend to be totally left sided, more detail oriented, and more directly to the point. Women, more often than not, use both sides, and tend to be more fluent, which may be why they have more to say. When husbands and wives get into arguments, their brain hemisphere activation styles often make problems worse. Because women use more words, men often become overwhelmed in disagreements and say insensitive things like “What’s the point?” or “Specifically, what do you want?” These statements infuriate women and make communication even more of a struggle. They know the point, they just have more to say about it with the extra input from the right side.

The female hormone estrogen encourages brain cells to develop more connections within the brain and between the two hemispheres. Because of these extra connections, women are better at multitasking. They can talk on the phone while watching TV, cooking dinner, and checking their e-mail. Men, on the other hand, are more compartmentalized and do best when they do only one thing at time. When a man stops his car to read a map, he asks everyone else to be quiet and turns down the radio. This allows him to focus. His wife usually doesn’t understand, as her brain can do, and actually enjoys doing, many things at a time.

Left-sided strokes, which affect the language area, tend to affect men more than women because many women have language on both sides of the brain. In one brain-imaging study, when
asked to judge whether nonsense words rhymed, men used only the left side of the brain, where more than half of the women used both sides. In another study done at the University of Indiana, when listening to a novel being read, men used the left side of the brain, where women typically used both sides.

The limbic system, or emotional brain, tends to be larger in women. The limbic system is the emotional bonding center of the brain. Therefore, it is no accident that women in overwhelming numbers are the primary caretakers for children. Likewise, women are primary caretakers for the elderly; 70 percent of elderly people who need care get it from a woman. The larger limbic size makes bonding easier for women. Women tend to have more friends in life, they go to church more often than men, and they pray (bonding with God) more than men. Women have a larger nesting instinct than men. They have a greater biological need to have their houses in order. When a couple moves, it is generally the woman who feels unsettled until everything is put away. Women are usually primary caretakers for the home and take on the bulk of housework. With the larger limbic size comes a greater incidence of depression. After puberty, females are three times more likely to develop depression than males. Women attempt to kill themselves three times more often than men. Yet men, due to lack of bonding and use of more violent means, kill themselves three times more often than women.