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.
achieving an erection : Tanagho 2000 found that when the penis is massaged or when a sexual fantasy occurs in the brain, an erection is initiated parasympathetic division of the 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 by the PNS, 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 skin-to-skin contact Erlandsson 2007.
promoting bonding: For more on between baby and parent, see
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 feel
s 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
O'Neill 2001, Fernald
Pancsofar 2008.
children, see Pecheux 1994, 1989, Grossman 2002, and
dads were more quirky Pecheux 1994. and fun: O'Neill 2001 and 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 involved 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 negative emotions are expressed, but accuracy when highly negative emotions are expressed. or moderately are similar in
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.
may cement a preference for it : Christakou 2009. For more on gender differences in empathy, see Schulte-Ruther 2008, Becker 2008b, and Eme 2007.
boundary between emotions of the "self" : Schulte-Ruther 2008 found that men's brains also have increased activation in the TPJ during the attribution of emotion to themselves, thus keeping a boundary between self and other.
off by a blank face : Schulte-Ruther 2008 found that there are gender differences in facial mimicry. The study shows more involvement of the MNS in females than in males during empathy-related face-to-face interactions. For more on gender differences in facial mimicry, see Dimberg 1990.
switches over to the TPJ: Schulte-Ruther 2008.
he did feel her distress: Schulte-Ruther 2008. system and share her emotions : Wild 2001. For more on gender differences in facial imitation and emotional contagion, see Sonnby-Borgstrom 2008. For a review on emotional contagion and emotional and cognitive empathy, see Nummenmaa 2008.
the unwritten laws of masculinity: Brod 1987. muscles to mask his fear : The facial muscles can reflect what is going on inside our brains, so learning to hide fear must be practiced. Males train their faces in gender-specific ways, as do females. But the unconscious moment of feeling or recognizing fear or contempt cannot be completely covered up, especially in a brain scanner--the ultimate lie detector. For example, Aleman 2008 says that the male brain reacts more strongly than the female to signals of status or hierarchy, especially to a look of contempt, for that is the universal facial expression of superiority.
emotionally reactive than the women : The unconscious mind subliminally triggers the facial muscles during an emot
ion, if only for a few milliseconds. These facial expressions are called microexpressions and can be measured by hooking detectors up to the facial muscles. For more on facial muscles and expressions, see Ekman 1978. Sonnby-Borgstrom 2008 found gender differences in facial-muscle information-processing (spontaneous/unconsious) emotionally regulated). The researchers also found that men consciously (supraliminally) suppressed emotions, but unconsciously, at first, they reacted more to their emotions--as evidenced only by the microexpressions in their frowning or smiling muscles.
responses representing
levels from subliminal to supraliminal (conscious/ subtle frown to a pout: Sonnby-Borgstrom 2008 found that women consciously (supraliminally) exaggerated their emotions, but unconsciously, at first, they reacted less to their emotions. For more on sex differences in smiling, see Hecht 1998 and Weyers 2009.
"... with logic instead of feelings?": For more on sex-related differences in brain activity during emotion regulation, see Mak 2009.
to run on different hormones: Holden 2004 and Eme 2007. for our different emotional styles : For more on gender differences in emotional styles, see Eme 2007, Baron-Cohen 2004c, and Hines 2004.
differently in men and women: Baron-Cohen 2004c and Eme 2007. men became temporarily more empathetic : Domes 2007 found that men's ability to infer the emotional and mental state of others improved after intranasal administration of oxytocin. For more on oxytocin, testosterone, and generosity, see Zak 2009. Barraza 2009 showed that oxytocin given to men increased empathy and generosity.
made them more mentally focused: Hermans 2008. than it is for women : For more on male brain circuits for anger, aggression, and physical fighting, see Lindenfors 2007, Eme 2007, Dunbar 2007a, and Williams 2006.
hormonally reinforced during the teen years : Eme 2007. For more on hormones and angry expressions, see Wirth 2007.
familiar part of his life : Eme 2007. For more on social and physical risk-taking in males, see Xue 2009, Fuxjager 2009, Wirth 2007, Carre 2008, and Hand 2009.