Although studies in the United States are few and far between, researchers in the Netherlands found that giving testosterone to men with abnormally low levels improved the men's physical and mental health. They found that it revived libido and penile function too. In addition, the men in the study had better muscle elasticity and bone density. They also reported improvements in their mood and their cognitive ability. And as a bonus, the study showed that increasing testosterone can kick-start abdominal weight loss.
I told Tom that research does show that exercising and staying sexually active can help men make more androgens, like dehydroepiandrosterone (DHEA) and testosterone. But for some men, that's still not enough. Being tired all the time and having foggy thinking aren't a natural part of getting older. When those symptoms are caused by abnormally low levels of androgens, some men get good results from androgen-replacement therapy. But its safety is still controversial, and it's not for everyone. For many men, there may be other answers.
In a study I conducted at UCSF in 1996, I compared the replacement of DHEA, an androgen similar to testosterone, with placebo in men over sixty. During this yearlong study, for an entire day once a month, the male subjects would come to UCSF's pleasant, spa-like clinical facility for testing. My friendly female nurses and psychologists would spend the day with the men while administering cognitive tests, collecting blood samples, and discussing details about their sex lives. Our results showed that by the end of the year, men taking the DHEA had improved their cognition, well-being, and sexual function by an impressive 40 percent. But the big surprise was that those taking the placebo had improved in all those same functions by 41 percent! I was forced to conclude that the therapeutic power of monthly social interaction with a group of caring, interested females was just as potent--or more so--to these andropausal men as the hormone DHEA.
A TIME FOR EVERY PURPOSE
When I told Tom about my study, he immediately understood that spending quality time with Diane might help him as much as hormone replacement. He said, "When Diane was going through menopause, the things you explained to us and encouraged us to do together made a big difference. But the hormones helped her too. How about if Diane and I come in to see you for some couples therapy again and I try the testosterone replacement too?" Tom wanted to keep his marriage and sex life going strong, so he was enthusiastic about doing whatever it took. And research confirms that men still rank sex as the major benefit of marriage, even into old age. So after discussing the risks and benefits with his primary-care doctor, Tom scheduled his first injection that very day.
When Tom and Diane came into my office together the next month, he explained that the testosterone-replacement therapy was helping but his "reliability" had slipped another notch. He said, "I don't want to be like this for the rest of my life. So I took my brother's advice and asked my doctor for Viagra."
Diane laughed and said, "I like the idea of Tom being happier with sex, but I'm not so sure I want him chasing me around the house again with that lustful look in his eye all the time."
Tom chuckled and said, "Okay, I'll only chase you around the house on weekends. The other days, I'll just chase you around the bedroom."
I could see Diane was happy that Tom was finding it easier to perform reliably again. And when I told her that drugs like Viagra, odd as it may seem, might even make him want to hold hands, cuddle, and hug more, her ears perked up. Researchers at the University of Wisconsin surprisingly discovered that drugs like Viagra can increase the release of oxytocin in the brains of rats by as much as threefold. Perhaps the famous blue pills will someday be used to promote deeper emotional intimacy and not just better erections.
Furthermore, as I reminded Tom and Diane, they could increase their oxytocin naturally by holding hands, gently stroking each other's skin and hair, massaging each other, and gazing into each other's eyes. Researchers showed that warm touching between partners improves satisfaction in relationships, and can actually make more of a health difference for men than women. In a "warm touch" study in Utah, researchers found that while both husbands and wives got a boost in their oxytocin levels and a reduction in stress chemicals, only the husbands got a beneficial reduction in blood pressure.
I also reminded Tom and Diane to practice the five-to-one rule: giving each other five compliments for every one critical remark. This was very important, because although Diane wanted Tom to be more affectionate, she admitted she had become more critical of him over the years. I said to Diane, "If you want Tom to hold hands with you and be more romantic, you have to be nice to him. And nice doesn't just mean sex."
Like Diane, women who have been married a long time know all their mate's foibles and flaws. The female brain tends to run negative scenarios to protect itself from disappointment and then place the blame on the male brain, like pinning the tail on the donkey. Constant criticism takes its toll on the brain. When a man's partner is critical of him, his brain goes on the defensive. His RCZ tells him that he isn't meeting her mark, and he begins to avoid contact. This creates a downward spiral that is a guaranteed dead end. It stops them both from getting the love and caring they crave. I knew using the five-to-one rule could make a positive difference for both Tom's and Diane's brains. And fortunately, in this case, the age of their brains would be working in their favor too.
According to scientists, older people don't let bad news or criticism get to them as much as younger people do. In a study comparing how the brains of seventy-year-olds versus twenty-seven-year-olds handle negative emotions, the older adults performed better. In particular, the researchers found that the brains of older adults had developed greater connectivity between the PFC, the area for regulation of emotions, and the amygdala, the area for driving emotional impulses. They concluded that the mature brain was not only better at controlling negative emotions but better at letting go of them. I said to Tom and Diane, "So, you see, it turns out that older brains are better at forgiving and forgetting." Tom quipped, "Maybe wisdom does come with age."
When I next saw Tom and Diane, they had just returned from a three-week European vacation. He gave me a thumbs-up, and she had a twinkle in her eye that I hadn't seen in years. It was nice to see them shifting comfortably into the next phase of their lives together.
THE GRANDFATHER BRAIN
The years after andropause are a major transition for the male brain. The fuels that are running a man's brain circuits change more toward oxytocin and estrogen and away from vasopressin and testosterone. Men are also winding down careers and looking for new and interesting projects to keep them busy and "in the game," or at least active on the sidelines. Up until maturity, many men can feel burdened by family commitments and even by their intimate relationships. But after andropause, they may, like Tom, have the time and temperament to appreciate family and friends more. Tom told me he felt a deep sense of satisfaction in having raised an accomplished daughter and that both he and Diane loved spending time with their grandson, Tommy.
To the amazement and delight of Diane and their daughter, Ali, Tom had recently morphed into a doting grandfather. Tom's mature brain had more patience with his grandson than he had ever had when Ali was growing up. The difference between Tom's daddy brain and his grandfather brain was working in everyone's favor. Much to even Tom's surprise, the love circuits in his mature brain were being hijacked by the adorable little Tommy, even more than they had been when Ali was born. The highlight of Tom's week had become cheering his five-year-old grandson on at his T-ball games. Soon, not even golf was as much fun as spending time with Tommy. He was amused by everything his grandson did and said. And he felt a deep pride in all of Tommy's developmental milestones and daily achievements.
One of my mentors, George Vaillant, found in his ongoing study of men who graduated from Harvard in the 1950s that in later years they changed their focus from activities that gave them a personal advantage toward activities that would give their community and the next generation an advantage. He calls this stag
e the fifth stage of individuation, or the stage of generativity. For many men like Tom, this position of a "wise elder" in their community includes the grandfather role, and a heightened interest in supporting the success and survival of the next generation.
Evolutionary anthropologists argue that grandfathers have been important for our species' survival. They found that in hunter-gatherer cultures, grandfathers can produce or procure more food than they consume, and therefore aid the flow of food from old to young. We now live in a world where the intelligence and knowledge of the grandfather--along with his financial assets, the modern equivalent of food--get passed on as his legacy to his kids, grandkids, and community. (In a typical example of the modern flow of resources from older generation to younger, Tom and Diane were helping Ali and her husband pay Tommy's private-school tuition.) But not all men find themselves particularly eager to take on the grandfather role. Researchers have shown that, at first, many men accept responsibility for grandchildren only out of a sense of obligation and love for their adult children. And research highlights how complex the nature of the ties between grandparents, their adult children, and grandchildren can be. For example, researchers have found that parents serve as gatekeepers and mediate the amount of contact and the quality of the relationship between grandparents and grandchildren. So a man's bond with his grandchildren depends on his relationship with his adult children. Tom was happy that his daughter facilitated his closeness with Tommy.
In many cultures, grandfathers also function to informally teach motor skills to grandchildren, for children learn best by imitation. And for Tom, not only did he love teaching his grandson how to throw and catch a baseball, he enjoyed teaching him about saving money and bought him his first piggy bank. He remembered how he got his own work ethic and the advice to save and invest his money from his immigrant grandfather, and he hoped to pass this on to Tommy. By the time his grandson was approaching his sixth birthday, Tom felt closer to him than he ever imagined was possible. He said, "If you'd have told me ten years ago that one of the highlights of my life would be having a grandson, I'd never have believed it."
Now that my husband, Sam, and I have entered this stage of life, with adult children and grandchildren of our own, we know exactly what Tom means. We find ourselves excited to interact with the grandkids as often as possible, chatting online by Skype and taking trips to see them. We feel more motivated than ever to make a difference in the lives of our family and the students and young faculty we mentor and teach. Sam and I have renewed our friendship and commitment as children have left home, come back home, married, and had grandchildren, and as a result, we are constantly finding a new balance. Of course, I can't see into our future, but the decades ahead beckon with hope, adventure, and passion for both me and Sam--the male brain I know best.
EPILOGUE
The Future of the Male Brain
IF I COULD impart one lesson to women that I learned in writing this book, it would be that understanding the biology of the male brain helps us relate better to the male reality. Much of the conflict that exists between men and women is fueled by unrealistic expectations that stem from failing to grasp each other's innate differences. To men, I would say I hope that shedding light on the male brain's tendencies and its physiological responses to hormones will clarify the basis for your natural urges and the way you think, feel, and communicate. My belief is that this information can provide men with a sense of relief at finally being understood.
Most people, men included, believe that the male brain's overriding goals are sex, status, and power--not necessarily in that order. And it is true that a tendency to seek these ends is built into the male brain's circuitry. But that is far from the whole story. Boys from the get-go learn differently than girls do and are interested in different things. Action, assertiveness, and rough play are biologically wired. We joke that men are run by their libidos, but the reality is that they are not slaves to their testosterone or sex drive. As we've seen, a man's sex drive may mature into a capacity for love and attachment that is at least as strong as a woman's. The stereotype of the stoic, unemotional male is again contradicted by research showing that the daddy brain and mature male brain are profoundly devoted and nurturing. And males don't start off less emotional. As infants, boys are actually more emotional than girls. But soon social pressures,
reshaping
child-rearing practices, and biology begin the male brain circuits. Teaching boys to
suppress their feelings and facial expressions, along with testosterone's influence, becomes "successful" by the time they reach manhood. This is a result of both training and biology. The male brain's response to emotions in others soon takes its own path, producing fix-it-fast solutions designed to alleviate distress.
On a personal level, I believe that learning about the male brain can help men and women feel more intimacy, compassion, and appreciation for each other. Such understanding might be the most important factor in creating a genuine balance between the sexes. I hope that this book will foster such understanding and help create more humane and civil societies wherever it is read.
APPENDIX
The Male Brain and Sexual Orientation
Are men gay because their brains are different? Studies have been conducted for two decades in order to answer this question. Some of them have found evidence of anatomical or functional differences between gay and straight brains. Others have established that genes play a part in determining gender orientation, which implies the existence of brain differences.
One of the early studies, by Dick Swaab, found that a part of the hypothalamus called the suprachiasmatic nucleus (SCN) is twice as large in gay males as in straight males. This difference was
difference in the way
developing brain. Other
later shown to be caused by a
testosterone reacts with the researchers showed that the anterior commissure--a bundle of superfast cables that connects the brain's two hemispheres--is larger in gay males than in straight males. This structure, which is also larger in women than in men, is believed to be involved in sex differences related to cognitive abilities and language, and fits with the finding that gay males, like females, have better verbal abilities than straight males.
Recently Ivanka Savic and other Swedish researchers reported that an anatomical asymmetry in the size of the two brain hemispheres that is characteristic of straight male brains is not observed in gay male brains. Instead, their magnetic resonance imaging studies showed that in this respect gay male brains were more like female brains. With PET scans, the researchers also found that the connectivity of the amygdala of the gay male brain is more like that of the straight female brain than of the straight male brain. These studies suggest that there are differences between gay and straight male brain areas that are not directly involved in sexual attraction.
Savic has also reported a different pattern of activation in gay male brains in response to a pheromone that is excreted in male perspiration. She found that the hypothalamus in gay male brains is stimulated by the scent of male sweat, but in straight male brains it is not. This suggests that a difference in the brain's hypothalamic circuits for response to pheromones may attract gay males to the scent produced by the sweat glands of men and that this plays a role in their sexual orientation. Other studies have found anatomical differences in the structure of the hypothalamus in gay and straight men.
There is also evidence of differences between gay and straight men in performance on certain spatial tasks. It has been consistently shown that straight men outperform straight women on tasks requiring navigation. Recent studies have shown that gay men perform more like straight women on such tasks.
Brain scans have also been used to measure activity changes in the gay and straight male brain when pictures of men and women were shown. Viewing a female face produced a strong reaction in the thalamus and medial prefrontal cortex of straight men but not of gay men. In contrast, the gay male brains reac
ted more strongly to the face of a man.
Genetic studies have also contributed some evidence of innate differences between gay and straight males. In a recent study, Dr. Niklas Langstrom estimated the part that genes play in gay male behavior by studying sexual orientation in adult male twin pairs. He found that identical twin pairs, who have all the same genes, are more likely to share sexual orientation than fraternal twin pairs, who share only half of their genes. Based on this comparison, he concluded that about 35 percent of sexual orientation is attributable to genetic influences, whereas the rest is due to as yet unidentified factors.
So far, none of the specific genes that influence sexual orientation have been identified, and researchers believe that the combined actions of many genetic and environmental factors will be involved. Furthermore, research on the brain circuits and on hormonal effects related to sexual orientation in humans is only just beginning. Nevertheless, the evidence we already have does show that some human brain differences are related not only to gendered behavior, but also to sexual orientation.
NOTES
INTRODUCTION: WHAT MAKES A MAN
What Makes a Man : Certain brain areas and functions are built differently in the male and female brains and have evolved over time to produce the most successful versions of men and women. For example, the brain circuits that alert us to danger (the amygdala) and help us remember it (the hippocampus) are the sources of sex and individual differences in emotional memory. In Hamann 2005, the authors found sex differences in the amygdala response during emotion-related activities, such as formation of emotional memory and sexual behaviors. And for more on the evolution of male and female brain circuits, see Lindenfors 2007 and Dunbar 2007: they say "... there are striking differences between the two sexes in the social mechanisms and brain units involved. Female sociality (which is more affiliative) is related most closely to neocortex volume, but male sociality (which is more competitive and combative) is more closely related to subcortical units (notably those associated with emotional responses). Thus brain units have responded to different different selection