I just finished reading Louann Brizendine's The Male Brain (2010)! Though I include gleaned insights on other posts, I detail most of what I learned below. Brizendine's The Female Brain is on my top five list of recommended reads- and this sibling volume maintained the reputation.
Caution: some of the content in this post is sexually explicit. Also, most of my notes fall between generalizations and overgeneralizations, inclusive.
The Baby Brain
> Male infants are less interested than female infants in eye contact and watching faces.
> Male infants are more interested in moving objects than female infants, which is at least partly due (not surprisingly) to some genetic material on the Y chromosome.
> Male infants have a year of "infantile pregnancy" where their brains are marinating in the same levels of testosterone they'll experience as adults. From year 1 to 11 they have a "juvenile pause" where they're relieved of testosterone exposure.
> By seven months, baby boys can tell mommy is angry by her face. By 12 months they've learned to ignore her expressions. Their female counterparts heed warnings on their mothers' faces. The same disparity applies to fathers' verbal warnings- the dads must verbally warn the boys twice as often as the girls.
> By 27 months, boys will go behind their parents' backs more often than girls to take risks, break rules, and grab off-limits objects.
> Little boy brains get a reward center hit from penis stimulation- and many little boys fail to resist playing and grabbing even when threatened.
>Boys reject girl toys, while girls will play with boys' toys. Rhesus monkeys do about the same thing, as do girls exposed to high testosterone in the womb.
> Boys spend 65% of free time in competitive games compared to 35% for girls. Girls are 20 times as likely to take turns when playing.
> Preschool boys are six times as likely to turn a domestic object into equipment or a weapon than girls.
THE TEEN BRAIN
> 20 fold increase of testosterone from 9 to 15
> Young boys think and explain with body movements and gestures more than young girls
> Boys cause 90% of the distractions in the classroom, 70% of the D's and F's, and account for 80% of high school dropouts
> Testosterone resets the brain's clock cells in the suprachiasmatic nuculeus, causing him to go to sleep and wake up an hour later than his female counterparts
> Teen boy brains need more intense shocking or scary stimuli to activate than adults
> Vasopressin, which teen boys get slammed with along with testosterone, causes them to perceive neutral faces as hostile toward them
> Higher testosterone levels are correlated with angier faces, more aggressive behavior, impatience, irritability, talking less about people, talking more about objects and games, and a suppressed sensitivity to white noise.
> During puberty, boys' rostral cingulate zone, the brain's barometer for social approval, recalibrates to motivate "fitting in" behaviors and seeking approval of peers over parents.
> Teen brains get a pre-game high right before participating or watching sports, characterized by elevated levels of dopamine, testosterone, vasopressin, and cortisol. Losing releases less testosterone than winning.
> By sixteen or seventeen, most boys desperately seek autonomy from their parents, usually accuse their parents of being behind the times, and seek separation/independence.
> Teen boys' risky behavior increases markedly in the presence of peers, with and without drugs or alcohol. The combination of 1) his amygdala's two-fold stimulation when he's with his peers and 2) his inhibiting system's (prefrontal cortex) failure to develop until early twenties is thought responsible.
> Teen boys begin to be repulsed not only by their mothers' proximity, but by her smell.
> From puberty to about 25, boys masturbate 1-3 times/day compared to less than one/day of girls
THE MATING BRAIN
> Male brains are selected for honing in on fertile females. Hourglass figures (large breasts, small waist, flat stomach, full hips) say she's young, healthy, and not pregnant.
> Flirting behavior are conserved across cultures, and thus likely brain-based (I knew this already. Thanks flirting symposium!). Examples include reciprocating posture, proximity, smiles, head tilts, and slight raising of eyebrows.
> A girl's smell and high-pitched voice may make her more sexually attractive. Low-pitch voice is less attractive, and the smell subconsciously communicates genetic dissimilarity, contributing to more attractiveness with greater dissimilarity.
> Smooching communicates info about genetic similarity as well. Also, the bioactive testosterone in the man's saliva may activate the female brain's sexual arousal center.
> When sexually attracted, a man wants to have sex three times faster than a woman, who's more patient. (I know, hide the surprise)
> Generally, a show of dominance and strength by a guy turns a girl on.
> Promiscuity vs. monogamy in voles depends on which of two vasopressin receptor alleles he has. Men also have this gene- and Swedish men with the "monogamy version" were twice as likely to leave bachelorhood behind and commit to one woman for life.
> Three out of four men are willing to lie or modify the truth to persuade women to have sex with them. They exaggerate wealth, status, and social/business connections.
> The male brain on sex: the ventral tegmental area rapidly manufactures dopamine, which mixes with testosterone and vasopressin to form an addictive, high-octane fuel comparable to being high on cocaine.
> The autopilot lust center of the male brain directs them to notice and visually take in details of attractive females, even when the man's in love with another.
> Fear of loss or rejection can intensify feelings of love by igniting the amygdala's fear-of-rejection center and the hypothalamus's mating area.
The Brain Below the Belt
> Woman want on average 1-2 sexual partners/lifetime; men a whopping 14.
> It takes the male brain one-fifth of a second to classify a new woman as hot or not. This appearance-based verdict is made even before conscious thought processes engage.
> Okay, careful, a few penis details: autopilot erections often happen without a single command from the brain- the unconscious signals come from his spinal cord and brain. The penis, testicles, brain, and spinal cord all harbor testosterone receptors. If testosterone is present, erotic thoughts or images are enough to signal an erection.
> Men are more sexually adventurous than women.
> Orgasm requires turning off the danger/alert center (amygdayla) and the worrying center (anterior cingulate cortex, or ACC). This process is more difficult for women than for men.
> Foreplay to men is the three minutes before orgasm, while for women it's the preceding 24 hours.
> After sex, oxytocin and dopamine make the girl want to cuddle and talk, while men more often want to sleep.
The Daddy Brain
> Distress after learning you're going to be a father usually peaks at about 5 weeks after discovering the fact.
> Men worldwide expereince a "sympathetic pregnancy," gain weight, and experience decrease in testosterone and increase in prolactin, especially in the three weeks preceding birth. The dads can also hear and emotionally respond better to a crying baby than non-dads. Hormone levels return to normal by the time the baby can walk.
> Skin to skin and eye contact with the baby causes both dad and mom to enter a romantic love phase with the child. Also, within a seventh of a second, the parental-instinct area of the brain is activated.
> Men, like women, have a strong tending instict based in the insula, ACC, and amygdala. Daily hands-on contact promotes synchrony, or parent-child understanding.
> Men interact more with the baby when mom's away or not watching.
> Moms are gatekeepers who determine how much baby time Dad gets, irrespective of Dad's belief about how involved he should be in child care. Interestingly, moms who let Dad have more baby time are more likely to stay married.
> Daddy's play is more physical, creative, unpredictable, and stimulating than Mom's. Rougher dads produce more self-confident kids.
> Dads like to tease their kids, and sons prefer it more than daughters. Kids with teasing fathers can better detect deceit, and sons can better build close male connections later in life.
> Cross-culturally, dads feel duty bound to discipline their kids, especially their sons. Generally, kids in these families get better grades and go farther in school, the sons have fewer behavior problems, and the daughters fewer emotional problems.
> Dads feel closest to their daughters and sons when helping them.
> Insecure dads won't let their sons beat them at any game even when the son is very young.
> High parental care correlates to less cortisol as a college-age adult.
Manhood: the Emotional Lives of Men
> I know you won't believe it, but the brain circuitry for emotional processing is different in men and women. Both genders have a temporal-parietal junction system (TPJ) and a mirror-neuron system (MNS). The TPJ separates "self" and "other" emotions and searches the brain for solutions. The MNS allows you to feel the emotion of another (emotional empathy). Guess which genders use which disproportionately. :)
> Women look at faces more to get an MNS response, and men resort more quickly to fixing-it-fast. When the male's face stops imitating the emotion of the woman (he's left the MNS), she feels he doesn't care - whereas the guy switched to TPJ and is trying to solve the problem.
> Men turn off or disguise their facial expressions to suppress showing their emotions. Females, on the other hand, exaggerate an observed emotion in another. These realities are correlated to estrogen/oxytocin for women and testosterone/vasopressin for men. Switch the hormones and you switch the MNS/TPJ ratio.
> Men's anger suppression center, the septum, is smaller than in women. Though women feel anger about as many minutes per day, men are 20 times as likely to get physically aggressive.
> Men and women remember facts equally well, but women remember details of emotional events better
and longer. Recalling events brings the emotion back for women much more than men.
> Some men get a high from being mucho angry.
> Sometimes, anger can make people more rational.
> High testosterone men are more likely to react dramatically to being challenged, which reaction can be triggered by glares, accusation, or yelling.
> Angry men get noticed more by both men and women.
> Couples who argue have a better chance of staying together.
> Mens' tendency to violence is dialed down by a stable work heirarchy and a stable marriage.
> Mens' brains are wired to seek status and rank.
> People prefer to feel potentially useful emotions, even when unpleasant. (e.g. anger)
The Mature Male Brain (no, that's not an oxymoron)
(Mature = andropause and beyond, circa 55 and up)
> As men age, testosterone and vasopressin levels drop and estrogen levels rise. Their brains become more like the mature female brain, including enhanced capacity for reading subtle facial expression.
> Less testosterone means a greater impact from oxytocin, leading to more patience, tolerance, cuddling, and less jockeying for position.
> Lonely people die sooner than same-age non-lonely pairs, and can be as detrimental to your health as
> Loneliness for men leads to decreased social flexibility and engrained habits, the disturbing of which leads to annoyance.
> Married men outlive single men by 1.7 years.
> Andropause takes place for men between 50 and 65, and includes a one-half to two-thirds drop in testicle-produced testosterone compared to levels in their 20's.
> Even into old age, men rank sex as the major benefit of marriage.
> Warm touching between partners, such as hand-holding and massage, improves relationship satisfaction, lower stress levels, higher oxytocin levels and, for men, lower blood pressure.
> Long-married couples are at risk for the woman criticizing the man, which prevents both from receiving the love and caring they crave.
> More mature brains are better at forgiving and forgetting.
> Grandfather brains care about supporting the success and survival of the next generation, though at first they accept responsibility for grandchildren only out of obligation.