The Male Brain (22 page)
Authors: Louann Brizendine
Tags: #Neuroendocrinology, #Sex differences, #Neuropsychology, #Gender Psychology, #Science, #Medical, #Men, #General, #Brain, #Neuroscience, #Psychology Of Men, #Physiology, #Psychology
center in a woman's brain
: Muir 2008 suggests that a man's excretions could be absorbed by a woman during kissing, touching, and skin-to-skin body contact and thereby affect her brain.
Nicole was being so cautious
: Hill 2002 found women more cautious about moving toward sex too soon and men needing less of a sense of emotional investment in the relationship before having sex.
: Buss 1993.
anything, least of all sex
: Roese 2006 found that women regret having sex early in the dating relationship more than men do.
offspring he's likely to have
: Buss 1993 found that men's wanting sex with many women has likely been evolutionarily selected for in males.
: Buss 2005 and Jensen-Campbell 1995.
and was willing to invest
: Griskevicius 2007 found specific mating goals increased men's willingness to spend money on conspicuous luxuries for women. They say that romantic motives produce highly strategic and sex-specific self-presentations. And Klapwijk 2009 found that generosity serves the important purpose of communicating "trust."
: Gomes 2009.
men, sex often comes first
: For more on gender differences in love, commitment, and sex, see Roese 2006, Sprecher 2002, Keverne 2007, Loving 2009, McCall 2007, Geary 2000, and Buss 1993.
(Uta stansburiana):
Bleay 2007.
"How can I pick a blue-throat?"
: Humans have a mating system scientists refer to as mild polygyny--multiple partners combined with a variable commitment to male parenting. Andrews 2008 found a sex difference in detecting infidelity--men are better at it. Atkins 2001a found that 20 percent to 25 percent of the married American population had had episodes of infidelity. Kontula 1994 found that in Finland, 52 percent of the men and 29 percent of the women reported episodes of infidelity in their lifetimes. They found that men reported being less emotionally involved than women with their infidelity partners, whereas the women seemed to connect both emotionally and sexually.
aggressively reject all other females
: Gobrogge 2007 found that passionate mating changes the male brain biologically forever and that it leads pair-bonded male prairie voles to reject new fertile females. They found that it is an interaction between dopamine and vasopressin that results in pair bonding in the male brain's hypothalamus and nucleus accumbens, NAc. For more on hormones, genes, and pair bonding, see Winslow 1993, Carter 1998, Liu 2001 and 2003, Lim 2004c, and Young 2009a. (In the female brain, it is oxytocin and dopamine that interact to produce pair-bond formation.)
preference for this one female
: For more on sex and partner preference in mammals, see Carter 1998 and Young 2008.
bond with their sexual partners
: Liu 2001 found that when experimenters gave a chemical to block the vasopressin receptor, it blocked the intercourse-induced pair bonding in the males.
in their brains couldn't merge
: For more on hormones in the brain, sex, and pair bonding, see Young 2008 and 2009b, Carter 1998, Becker 2008b, Wang Z. 2004, and Pfaff 2002.
vole, he, too, became monogamous
: Lim 2004c experimentally induced pair-bond formation in the promiscuous vole by inserting the vasopressin gene from the monogamous prairie vole into the promiscuous vole.
this vasopressin receptor gene too
: For more on the vasopressin receptor gene in humans, see Aragona 2009, Adkins-Regan 2009, and Walum 2008.
to one woman for life
: Walum 2008 found an association between one of the human vasopressin receptor genes and traits reflecting pair-bonding behavior in men. They showed that the vasopressin genotype of men also affects marital quality as perceived by their wives.
: Haselton 2005.
Haselton 2005.
: Reviewed in Shackelford 2005d and Buss 2005b.
: For more on female brain, oxytocin, and pair bonding, see Liu 2003.
the more he squirmed
: Loving 2009 found an increased stress reaction in men when discussing commitment or marriage.
: O'Hair 1987.
couldn't get enough of her
: Gillath 2008a found that sex increases the desire to share personal information, fosters intimacy-related thoughts, and promotes a willingness to sacrifice for one's partner. Klusmann 2002 found that although sexual activity and sexual satisfaction decline in women and men as the duration of the partnership increases, sexual desire declines only in women, not in men. (And the desire for tenderness declines in men and rises in women.) They conclude that a stable pair bonding does not require high levels of sexual desire for women, after an initial phase of infatuation has passed. But for men the opposite is true. They found that male sexual desire should stay at a high level because it was selected for in evolutionary history as a precaution against the risk of sperm competition.
: For more on the male brain, pair-bond formation, and intercourse, see Liu 2001.
getting a primitive biological craving
: For more on the specific brain areas where dopamine exerts its effects on pair bonding, pleasure, reward, and motivation, see Curtis 2006.
neurotransmitter for motivation and reward
: Aragona 2009 found that dopamine transmission mediates the formation and maintenance of monogamous pair bonds. For more on motivation and reward in pair-bond formation, see Kruger 1998, Exton 2001a, and Young
anticipation of pleasure and reward
: Knutson 2008 found that the nucleus accumbens (NAc) activation increases during anticipation of pleasure and deactivates during anticipation of loss in a relationship.
mixed with estrogen and oxytocin
: Both males and females have oxytocin, vasopressin, testosterone, and estrogen, but the ratios are sex-specific and controlled by genes, proteins, and enzymes like aromatase. For more on the male brain, estrogen, and aromatase, see Wu 2009. For more on pair-bond formation in males and females, see Liu 2003, Bocklandt 2007, Becker 2008a, and Carter 2008.
: For more on the brain and intense romantic love, see Aron 2005 and Fisher 2005 and 2006.
: Gonzaga 2006.
: Fisher 2004.
they focused only on Nicole
: Fisher 2006 found that when the in-love subjects looked at their beloveds, men also showed positive activity in a brain region associated with erection hardness. This means that the male love-response directly links romantic associated with sexual describes specific brain circuits for unconditional love. passion with a brain region
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
and possessive mating instincts wild
: For more on mating instincts and hormones, see Carter 2007 and 2008, Becker 2009, and Pfaff 2002.
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.
: 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.
: 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.
: 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.
: Lee 2006 and Moulier 2006.
: For more on vaginal penetration and condom use, see Crosby 2007.
: Arnow 2002 and Holstege 2003.
: 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.