The Male Brain

by Louann Brizendine, M. D.

to hold on to her: Buss 2002 says that the male must be fending off potential mate poachers and preventing his mate from defecting to hold on to the female. He found that mate-guarding adaptations evolved to avoid suffering negative reproductive costs, ranging from genetic cuckoldry to reputational damage to the permanent loss of a mate, and that male mate-guarding behaviors can range from vigilance to violence.

  happen several times a day: For more on the male brain, lust, and visual sexual attraction circuits, see Fisher 2002, 2005, and 2006.

  imagined Frank hitting on her: Rilling 2004 reviews sexual jealousy in males. Little 2007 and Burriss 2006 found that men sense a preference shift in their female partners toward more masculine men at ovulation. For more on male sexual coercion, see Starratt 2008 and 2007.

  a tactic called mate-poaching: Schmitt 2004 found that the patterns for men in mate-poaching are similar across fifty-three nations. And they found that women poach too. Parker 2009 found that when a man was described as “unattached,” 59 percent of the single women were interested in pursuing him, but when that same man was described as “being in a committed relationship,” over 90 percent of the women expressed interest in the guy.

  intensify our feelings of love: For more on rejection intensifying emotional commitment, see Baumeister 2001, Eisenberger 2004, Macdonald 2005, and Fisher 2002.

  and possessive mating instincts wild: For more on mating instincts and hormones, see Carter 2007 and 2008, Becker 2009, and Pfaff 2002.

  FOUR: THE BRAIN BELOW THE BELT

  average of one or two: For more on men wanting a greater number of short-term sexual partners, see Schmitt 2001.

  interest in one-night stands: For more on one-night stands, see Schmitt 2001, Laumann 1999b, and Mulhall 2008a. For more on men’s satisfaction with their sex life, see Colson 2006, who found that almost 70 percent of men reported that they wished to change some things about their sexual life.

  men’s testosterone levels to go up: Van der Meij 2008.

  as sexually hot—or not: Ortigue 2008 found that the male brain’s decision about desirability of sexual stimuli occurs within the first 200 milliseconds after seeing a woman. This means it occurs before conscious processing.

  way their penis is shaped: Sanchez 2007.

  happy with their partner’s size: Lever 2006 surveyed 52,031 men and women and found that many men wished they had a larger penis. And only 2 out of 1,000 men wished their penis were smaller. Dillon 2008 found that penile size is a considerable concern for many men from teens to old age. Wessells 1996 found that neither a man’s age nor the size of his flaccid penis accurately predicted erectile length. But stretched penis length most closely correlated with erect penis length. For more on penis size, see Francken 2002.

  is their most important feature: Francken 2002 found that a great many men believe that the size of the penis is directly proportional to its sexual power.

  larger than it needs to be: Diamond 1997 notes that since the penis only has to be able to fit into a woman’s vagina, men with penises that are too large may not be able to sire as many offspring, thus making larger penises undesirable.

  from 5.5 to 6.2 inches: Wylie 2007 found that the average erect penis is 5.5 to 6.2 inches long and that an average-sized man is likely to be troubled by concerns that his penis is not large enough to satisfy his partner or himself and to be ashamed to have others view his penis, especially in the flaccid state.

  to their females, it’s supersize: Diamond 1997 describes that, compared with other mammals, the human penis is larger than necessary.

  conscious desire to have sex: Janssen 2008 found in his survey that most men say that they can experience erections without feeling aroused or interested.

  to start an erection: Tsujimura 2006. Holstege 2003 found that erection starts as a man imagines having sex with his partner or with other women in any of various positions and locations, both indoors and out. For more on erection, see Janssen 2008, Baskerville 2008, and Schober 2007.

  “order for him to function”: Beach 1967 found that none of this circuitry for sexual arousal or erection works in males who are deprived of testosterone. Steers 2000 found that it is testosterone, along with oxytocin and neurochemicals like dopamine, acetylcholine, and nitric oxide, that acts within the brain, spinal cord, and penis to produce an erection. Swann 2003 found that in the male brain, there is a sexually differentiated, testosterone-responsive network that relays signals to the muscle-control areas to produce copulation. For more on intercourse, see Redoute 2005.

  men to become fully erect: Miyagawa 2007.

  the hormonal engines for erection: Mouras 2008 found that while being shown sexual video clips, 8 out of 10 healthy men registered an erection, as demonstrated by a measuring cuff around the penis.

  hope of a sexual reward: The nucleus accumbens (NAc) is a major center in the brain for anticipation of reward. For more on sex and reward, see Ponseti 2009 and Paredes 2009.

  “pay total attention to this now” circuits: Lee 2006 and Moulier 2006.

  one smooth thrust, he was inside: For more on vaginal penetration and condom use, see Crosby 2007.

  sexual tension, arousal, and pleasure: Arnow 2002 and Holstege 2003.

  and fellatio twice as often as women: Laumann 1999b.

  becomes less and less sensitive: Payne 2007. Shafik 2007 found that stimulating the urethral opening keeps the nerves and muscles of the penis activated to maintain a throbbing, hard erection, thus enabling a forcefully ejected stream of semen, which has a better chance of impregnating the woman.

  from pain during sexual intercourse: Payne 2007.

  neurochemical stars need to align: Murstein 1998 found that men score higher than women in studies of sexual interest, frequency of sexual arousal, and sexual enjoyment.

  happens three minutes before entry: Meston 2004. For more on women’s orgasm, foreplay, and vaginal-penile intercourse, see Weiss 2009. For more on female sexual function and dysfunction, see Basson 2005.

  penis or clitoris to orgasm: Georgiadis 2009. Muehlenhard 2009 found that both men and women pretend or fake orgasm—females 67 percent and men 28 percent of the time during penile-vaginal intercourse.

  periaqueductal gray (PAG)—activated intensely: Parra-Gamez 2009 and Georgiadis 2009 found that the only prominent gender difference during orgasm was greater male activation of the PAG—the area for decreased pain and sexual moaning. Holstege 2003 found that brain scans taken of men while they are ejaculating show vivid activations in the ventral tegmental area (VTA), where dopamine is made.

  problems of his early twenties: Revicki 2008 found that up to 75 percent of men ejaculate within ten minutes of penetration. Richters 2006 found that men had an orgasm in 95 percent of sexual encounters and women in 69 percent. Weiss 2009 found that women’s likelihood of orgasm during intercourse increases when penile-vaginal penetration lasts longer. For more on female sexual function, see Meston 2004, McKenna 2000, Mong 2003, and Basson 2005.

  or off by the brain: Truitt 2002. Beaureguard 2009 found that the anterior cingulate cortex (ACC), the worrywart center, is alerted to the impending erection. This heads-up in the ACC lets it team up with other brain circuits, like the insula, or disgust center, to turn off the spinal erection generators when necessary.

  seven to thirteen minutes or more: Waldinger 2005. Corty 2008 found that the normal, average length of intercourse is 3 to 13 minutes. Sex therapists recommend that men use Kegel squeezing exercises, masturbation, and mental distraction during intercourse, or condoms and penile-numbing gel if necessary, to treat rapid ejaculation. SSRI medication is also available to slow down ejaculation and help males last longer. However, SSRIs can prevent sexual arousal entirely.

  experienced it at least once: Symonds 2007 and Revicki 2008. The diagnosis of PME, premature ejaculation, is made only when a lack of ejaculatory control interferes with sexual or emotional well-being in one or both partners. For more on the treatment of PME, see Sadeghi-Nejad 2008.

  ac
hieving an erection: Tanagho 2000 found that when the penis is massaged or when a sexual fantasy occurs in the brain, an erection is initiated by the PNS, the parasympathetic division of the autonomic nervous system. These PNS nerve branches cause the release of nitric oxide in the penis, dilating the arteries to fill it with blood and become hard. Viagra-like medicines act on the nitric oxide system to aid erections. Erection stops when the parasympathetic stimulation is discontinued and the SNS, the sympathetic division of the autonomic nervous system, starts constriction of the penile arteries, forcing blood out and making the penis get soft.

  get the erection he wanted: Tanagho 2000. For more on erections, see Brody 2009 and Costa 2009.

  triggering the brain’s sleep center: Veenema 2008 found oxytocin is released in the male brain, during and after sex, for up to four hours, thus increasing sedation and relaxation and decreasing anxiety. For more on oxytocin and sex, see Waldherr 2007.

  FIVE: THE DADDY BRAIN

  they’re going to be fathers: Buist 2003. Morse 2000 studied 327 healthy couples and found that some dads-to-be reported being distressed during the pregnancy about the relationship, performance failure at work, and/or sex.

  “the rest of its life”: Ahern 2009 and Meaney 2005. Boyce 2007 found that fathers who had insufficient information about pregnancy and childbirth were at risk of being distressed, suggesting that more attention needs to be paid to providing information to men about their partner’s pregnancy, childbirth, and issues relating to caring for a newborn infant.

  down and prolactin goes up: Gray 2006. Exton 2001b found that increased prolactin in males reduces sex drive. They suggest that prolactin goes up and testosterone goes down in dads-to-be in order to reduce sexual interest at a time when fertilization is not possible. For more on male hormones in pregnancy, see Delahunty 2007, Ma 2005, Burnham 2003, Wynne-Edwards 2000 and 2001, Carlson 2006, and Fleming 2002.

  from the mother-to-be’s skin and sweat glands: Vaglio 2009 found that during pregnancy, women develop a distinctive pattern of five volatile, odorous compounds in their sweat glands and skin that may act as pheromones.

  “sympathetic pregnancy”: Klein 1991 found that couvade is a common but poorly understood phenomenon whereby the expectant father experiences physical symptoms during his mate’s pregnancy, like indigestion, increased or decreased appetite, weight gain, diarrhea or constipation, and even headache and toothache. Ziegler 2006 found that couvade occurs in other dad-to-be primates. In the study, expectant males showed significant increases in weight during the pregnancy, whereas control males did not. For more on couvade, see Conner 1990.

  growth of maternal brain circuits: Larsen 2008 found that in female mice, contact with male pheromones caused new brain cells to grow in the female brain’s frontal lobe in an area for maternal behavior. The data suggest that male pheromones stimulated a prolactin-mediated increase in brain cell growth in female mice, resulting in enhanced maternal behavior. For more on female brain and maternal circuits, see Becker 2008a.

  the three weeks before birth: Storey 2000.

  to crying babies than non-dads: Gray 2007.

  fathers give very little care: Muller 2009. See Winking 2009 for fathering care in Bolivian men.

  calming them and promoting bonding: For more on skin-to-skin contact between baby and parent, see Erlandsson 2007.

  fell in love with Blake: For more on the brain and parental love, see Swain 2007, Feygin 2006, and Leckman 2004.

  each other’s eyes and faces: For more on the brain and parenting, see Leckman 2004.

  a seventh of a second: Kringelbach 2008.

  before the dad feels compelled: For more on parental responses to crying, see Bos 2010 and Fleming 2002.

  as he heard Blake crying: Swain 2007 and 2008.

  day, for the first month: Kozorovitskiy 2006. Also see Kinsley 2008 and Fleming 1999.

  hormones: prolactin, oxytocin, and vasopressin: Kozorovitskiy 2006. Also see Berg 2001, Proverbio 2006, and Kuzawa 2009.

  child also activates the PFC: See Kozorovitskiy 2006 for overview.

  studies by Dr. Ruth Feldman: Feldman 2002 and 2007.

  difference between Mommy and Daddy: Bretherton 2005. McElwain 2007 found that children (especially boys) benefit when parents differ in their reactions to their kids’ emotions.

  mother’s bond with her baby: Matthiesen 2001 found that periods of increased massage-like hand movements or sucking of the mother’s breast were followed by an increase in maternal oxytocin levels.

  differently to Mom and Dad: Feldman 2003 and 2007.

  games Tim played with him: Feldman 2007.

  playtime was much more spontaneous: Cannon 2008.

  were in the driver’s seat: Schoppe-Sullivan 2008 found that moms are ultimately the gatekeepers for the dads’ access to kids. They also found that fathers who are in more harmonious marriages are more affectionate toward their infants. For more on marriage and parenting, see Fagan 2009.

  could look to for help: Silk 2009 found that the help females receive from their own mothers and adult daughters—and other female kin—has a significant influence on children’s survival and well-being. For more on parenting, female kin, and child survival, see Kendler 2005, Taylor 2000, Hill 2003, Hawkes 2004, Sear 2008, and Gurven 2009.

  it comes to staying together: Pasley 2002 found that dads who perceived their wives as evaluating them positively as fathers were likely to have more commitment to the marital relationship. For more on marital relationship and parenting, see Roopnarine 2005.

  improves their ability to learn: Feldman 2007.

  unpredictable and thus more stimulating: For more on fathers stimulating their children, see Pecheux 1994, O’Neill 2001, Fernald 1989, Grossman 2002, and Pancsofar 2008.

  dads were more quirky and fun: O’Neill 2001 and Pecheux 1994.

  the time they reached adolescence: Grossmann 2002 found that in their sixteen-year longitudinal study, fathers’ sensitive and challenging play was a key variable in a child’s success. For more on children’s success and fathering, see Sarkadi 2008.

  recognize mental tricks and deceits: Bretherton 2005.

  more direct orders than mothers do: Abkarian 2003. 90 need the way Mom does: Fernald 1989.

  especially sons, toe the line: Sarkadi 2008.

  the hormones testosterone and vasopressin: Wang Z. 1993 found that having no testosterone at all, due to castration, reduces paternal behaviors. Brain connections in castrated male mammals for paternal behavior became reduced due to fewer vasopressin cells in the brain.

  be better, more protective dads: Frazier 2006. For more on brain motivation and paternal care, see Devries 2009 and Becker 2009.

  dads who were not disciplinarians: Sarkadi 2008.

  with men later in life: Wiszewska 2007.

  always more negotiating and compromising: Tannen 1995. Leaper 1998 found that in studies of two parents with their children, there was greater talkativeness of mothers to their children than of fathers.

  doing something to help them: Bretherton 2005.

  their sons are very young: Leckman 2004 and Feldman 2002.

  high parental care in childhood: Pruessner 2004.

  bonding parent to child: Feldman 2002.

  SIX: MANHOOD: THE EMOTIONAL LIVES OF MEN

  parts of our basic biology: Kozorovitskiy 2005.

  temporal-parietal junction system, or TPJ: Shamay-Tsoory 2009 found two systems for empathy: one for cognitive empathy, the other for emotional empathy. Schulte-Ruther 2008 found gender differences in brain networks for empathy. The TPJ is a hub where many circuits for attributing mental states to others converge and diverge, for example, the superior temporal sulcus, medial prefrontal cortex, and others. For more on hubs in the brain, see Thioux 2008 and Immordino-Yang 2009. The MNS, the mirror neuron system, which is spread out through many brain regions in humans, helps us understand how others feel, how they act, and what they will do. Structures within the human mirror neuron system are found to be i
nvolved in sharing gestures and facial expressions. Zaki 2009 found that using these two sets of brain regions helps us accurately track the attributions we make about another’s internal emotional state. Yuan 2009 found that men make less accurate judgments than women when subtle or moderately negative emotions are expressed, but are similar in accuracy when highly negative emotions are expressed.

  use the other system more: Schulte-Ruther 2008 found increased neural activity in the TPJ, temporal-parietal junction, in males; and found that females showed increased activation of the MNS, specifically the inferior frontal mirror neurons. Thus, females recruited areas containing mirror neurons to a higher degree than males during emotional processing in empathetic face-to-face interactions. Witelson 1991a found that the temporal-parietal region, TPJ, of the brain is larger in males. Cheng 2009 found that females perform better in empathy, interpersonal sensitivity, and emotional recognition than do males, perhaps since the mirror neuron system, MNS, plays an important role in these processes. The researchers found that young adult females had significantly larger gray matter volume in the mirror neuron system than did males. Yuan 2009 hypothesizes that the larger female MNS may result in more emotional contagion—or infectious feelings—and empathy in the average female than in the average male.

  This is called emotional empathy: Bastiaansen 2009. The capacity that humans have to intuitively grasp the mental states of other individuals is important for social functioning. Even when people’s more subtle emotions remain puzzling, we can have gut feelings of what is going on in them. The MNS plays a major role in this skill.

  This is called cognitive empathy: Cognitive empathy means intellectually understanding what is upsetting to the other person in front of us—but not feeling that same feeling in our gut. This mental separation of one’s own perspective from that of another person helps us to disentangle our own feelings from those observed in other people and to figure out the solution to an emotional problem without becoming “infected” with their emotions. The TPJ hub is involved with doing this. For more on keeping one’s own emotions separate and the TPJ in males, see Schulte-Ruther 2008.