The Male Brain

by Louann Brizendine, M. D.

  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 the number of nocturnal erections, sexual thoughts and motivation, number of successful intercourses, scores of erectile function, and overall sexual satisfaction, 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 might have beneficial effects on body composition (losing fat), muscle strength, sexual function, and cognition.

  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.

  marriage, even into old age: Laumann 1999a.

  “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 negative (the Gottman technique) had marriages that survived and even improved.

  letting go of them: St. Jacques 2009.

  “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.

  food from old to young: Kaplan 1997.

  love for their adult children: Roberto 2001.

  their adult children, and grandchildren: Kivett 1998.

  relationship between grandparents and grandchildren: Silverstein 2001 and Szinovacz 1998b. Jiang 2007 found that grandparents were dominant in shaping children’s eating behavior in three-generation families.

  APPENDIX: THE MALE BRAIN AND SEXUAL ORIENTATION

  males as in straight males: Swaab 1990.

  reacts with the developing brain: Swaab 1995.

  males than in straight males: Allen 1992.

  of the straight male brain: Savic 2008.

  in gay and straight men: LeVay 1991 and Kinnunen 2004.

  straight women on such tasks: Rahman 2005 and 2008.

  to the face of a man: Swaab 2009.

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