The Male Brain (25 page)

listener, and be more affectionate
: Burri 2008 found that when oxytocin was increased in men, the men's sexual arousal increased. And when the men in the study were asked about their subjective perception of whether oxytocin or placebo had been applied, eight out of ten subjects in the oxytocin group answered correctly, thus pointing to an altered perception of sexual arousal by oxytocin.

as his testosterone production declined
: Johnson 2006 found that higher testosterone increases the drive to outdo other men.

no longer worth it to him
: Winning and losing may not matter so much, and cooperation may matter more to men as their testosterone levels mellow out. Mehta 2009 found that high-testosterone men are motivated to gain status (good performance in individual competition), whereas low-testosterone men are motivated to cooperate with others (good performance in intergroup competition). So with age, a man's need for dominance may have biologically subsided.

meant more than being lovers
: For more on the hormones of pair bonding, see Young 2009 and Carter 1998. Kendrick 2000 found that after sexual intercourse, in the female the stimulation of the cervix and vagina, along with orgasm, causes a coordinated release of oxytocin in the brain that acts to increase maternal and pair-bonding behaviors lasting for up to one hour.

she is no longer fertile
: Tuljapurkar 2007 found that female menopause, around age fifty, should theoretically be followed by a sharp increase in mortality for humans, a "wall of death." Their analysis showed that older men reproducing with younger women throughout evolution is what forms the basis for increasing human longevity in both sexes. For more on the genes of longevity, see Emery 2007.

engraved into their brain circuits
: It turns out that for men, health and marriage are more connected than for women because men get most of their social interaction after retirement via their wives' social connections and social planning skills. For more on the brain and aging, see Decety 2009, Dedovic 2009, and Cacioppo 2009a.

circuits are weakened from disuse
: Decety 2009 found that men need to use their social and emotional cognition and problem-solving circuits, or else their temporal-parietal junction (TPJ) will atrophy. The TPJ is associated with cognitively taking the perspective of another person, which happens only if other people are around to activate that part of the brain. Also see Cacioppo 2009b.

people who are socially isolated
: Cacioppo 2009b found that the brain's TPJ is much less activated among the lonely than in the nonlonely. And the lonely also activate their brains' reward circuits less. So they begin to get less pleasure out of interacting with others, and their brains' social circuits may become less responsive if they stay lonely too long.

get married and stay married
: Willcox 2006 found that before age eighty-five, the lack of a marital partner is associated with increased mortality. Schmitt 2007 found that marital satisfaction well-being and that a interaction is particularly important in predicting marital satisfaction and long marriages.
is important for health and

men live 1.7 years longer
: Smith 2009 found that marriage factors and health differ for men and women throughout the life span because being married shortens a woman's life by 1.4 years but lengthens a man's by 1.7 years. The study found that bad marriages, with lots of arguing and negative feelings, make both sexes stressed but cause physical illness only in wives. The men in bad marriages reported stress and reported being depressed, but their physical health didn't seem to be affected. For more on marriage and health, see Kiecolt-Glaser 1998, 2001, and 2005, Gabory 2009, Behar 2008, Willcox 2006, Felder 2006, and Levenson 1993.

make a man a man
: Beach 1967 found that the male brain's sexual-pursuit and arousal circuits must be primed for action by testosterone in order for the man to function. For more on testosterone and sexual function, see Moffat 2007.

so-called andropause, or male menopause
: Sharma 2009 found that the benefits of treating severely low testosterone are well established. Milder forms of low testosterone in the aging male, known as andropause, are common starting in the fifties and sixties. Researchers say that testosterone replacement therapy may produce a wide range of benefits for men, including improvement in libido, bone density, muscle mass, body composition, mood, and cognition. But they say there is no definitive verdict on the balance between risks and benefits of testosterone replacement therapy in aging males. For more on testosterone replacement in the aging male, see Lapauw 2008, Anawalt 2001, Qian 2000, Heaton 2001, Lincoln 2001, Hogervorst 2009, and Van Strien 2009.
of life also includes sex
: Smith 2007 found that desire for sexual activity remained high among men seventy and older. Colson 2006 found that almost 70 percent of men reported they would like to change some things about their sex life. Kontula 2002 found that, especially with the increased duration of the relationship, the frequency of masturbation actually increased in men who were in long-term partnerships, even if penile-vaginal sex was occurring regularly. Beaulieu-Prevost 2007 found that men after age forty continue to have reflexive erections while they're sleeping. Eight percent of older men's dreams were about intercourse and resulted in nocturnal erection. Laumann 1999 found that masturbation increased in older men because their current partner did not want sex; this was three times more often in men than in women.

at this stage in life
: Siegel 2007 found that sexual changes that occur in men as they get older affect their self-perception and sexual identity. Janssen 2008 found that changes in the quality of older men's erections had a direct effect on their sexual encounters, including, for some, a shifting of focus to the partner and her sexual enjoyment. In this study, older men said that as they aged, they became more careful and particular in choosing sexual partners.

they produced in their twenties
: Tanagho 2000 found that a man's testosterone peaks at about age seventeen; then it plateaus at a high level for a while and may slowly start to slide by the thirties and forties; then, by eighty, his testosterone may be less than half of what it was when he was young. Vermeulen 1999 says that as age increases, a man's body fat increases and his testosterone goes down. For more on testosterone and aging, see Qian 2000, Araujo 2007, and Laughlin 2008. For approaches to evaluating and treating men with low testosterone, see Snyder 2008.

quickly becoming a marital problem
: For comprehensive research data on age, couples, and sex, see Laumann 1999. Erectile dysfunction (ED) is a common condition estimated to affect more than 150 million men worldwide. Doctors now believe ED should be regarded as a shared sexual problem because it has significant detrimental effects both on the men who experience it and on their partners. So the wives or partners should be included in treatment decisions for Viagra-like drugs or testosterone. Isidori 2005a found that in older men with sexual complaints, testosterone treatment moderately improved
thoughts
the number of nocturnal erections, sexual and motivation, number of successful

intercourses, scores
sexual satisfaction,
of erectile function, and overall but that in men with normal

testosterone levels at the beginning, the testosterone had no effect on erectile function compared to placebo. Mulhall 2008b found that 74 percent of men were willing to take erection-enhancing drugs if necessary. For more on treatment, see Wang P. 2009 and Sharma 2009.

organs working at full capacity
: Redoute 2005 found that the brains of men with very low testosterone did not light up in the areas necessary for sexual arousal as they watched sex movie clips in the brain scanner. But after the males were injected with testosterone, these brain areas flashed back on again.

testosterone can kick-start abdominal weight loss
: Gooren 2009. Srinivas-Shankar 2009b found that testosterone treatment in older men with low levels of testosterone composition function, and cognition. might have beneficial effects on body

men, that's still not enough
: For more on DHEA, androgens, and aging, see Rainey 2008, Baker 2006, Dharia 2004, Anawalt 2001, Parker 1999, and Sapolsky 1993.

results from androgen-replacement therapy
: Cherrier 2007 studied the cognitive responses of older men in whom moderate or large increases in serum testosterone levels were induced by testosterone supplementation, and found that those with moderate testosterone replacement did better on cognitive tests.

and it's not for everyone
: Wang P. 2009 says men must be monitored closely for prostate function and for prostate and breast cancer when considering or being prescribed testosterone replacement.

there may be other answers
: Exercise, lowered stress, loving relationships, and healthy diet are well-proven aids to healthful aging in both men and women. Also see Roberts 2008.

men as the hormone DHEA
: Unpublished data. Soma 2008 found that the adrenal androgen precursor dehydroepiandrosterone (DHEA) may be important for the expression of sexuality and aggression when gonadal testosterone synthesis is low. DHEA is metabolized into active sex steroids, both in the periphery and within the brain itself. For more on DHEA in development and aging, see Parker 1999.

"asked my doctor for Viagra"
: Rosen 2006 found that for mature men, Viagra started a revolution, and this was true even for older men who did not have ED (erectile dysfunction). This is because older men now get the message: "Other guys are having a lot of sex as they get older. Why not me?" The researchers also found that the outcome in men with erectile dysfunction could be helped or hindered by their partners or wives.

as much as threefold
: Zhang 2007 found a surprising result. These so-called impotence drugs not only block the PDE-5 enzyme to aid erection, but can also boost levels of oxytocin.

beneficial reduction in blood pressure
: Holt-Lunstad 2008 found that the influence of a warm touch enhancement intervention among married couples improves blood pressure, oxytocin, alpha amylase, and cortisol. But only husbands in the intervention group had significantly lower post-treatment twenty-four-hour systolic blood pressure than the control group. McGlone 2007 found that soft touches also activate a class of slow unmylenated nerves that send messages back to the brain's insular cortex, limbic system, and orbitofrontal cortex. These nerves give a pleasant sensation from light touch, and when the skin is lightly stroked, the brain interprets it as emotional touch.

for every one critical remark
: Gottman 2006 found that the marriages of couples having a videotaped conflict were more likely to survive if they made roughly five positive, complimentary comments for every one negative, critical comment. Carrere 1999 found that it was possible to predict a good or bad marital outcome over a six-year period using just the first three minutes of data. They found that couples who used a ratio of five positive comments to one technique) had marriages improved.
negative (the Gottman

"wisdom
does
come with age
": Mather 2005 found that as people get older, they experience fewer negative emotions. They say that this "positivity effect" in older adults' past memories, compared with younger people, seems to be implemented by cognitive control mechanisms that enhance positive and diminish negative thinking. For more on the positivity effect in older brains, see Ashley 2009, Charles 2008, Nielsen 2008, Dreher 2008, and Samanez-Larkin 2007.

The Grandfather Brain
: Szinovacz 1998b found that grandparenthood is initially a dual process signifying both the transition to parenthood for the adult child and the transition to being a grandparent for his/her parents. For more on similarities in the responses of men and women to grandparenthood, see King 1998b.

been when Ali was born
: Beauregard 2009 found that the neural basis of unconditional love shows that romantic love and parental love are mediated by regions specific to each, as well as overlapping regions in the brain's reward system.

or the stage of generativity
: Vaillant 2002. Vaillant wanted to explore how men adapt to circumstances over a lifetime. The average age of the Harvard men is now eighty-seven. He has concluded that in these men, sustaining warm, close relationships turned out to be a powerful predictor of successful aging.