The Male Brain (24 page)

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.

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.

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 emotion, 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.

for our different emotional styles
: For more on gender differences in emotional styles, see Eme 2007, Baron-Cohen 2004c, and Hines 2004.

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.

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.

and body for a fight
: Becker 2009. For more on testosterone changes and power motivation in victory versus defeat, see Schultheiss 2005. For more on anger and driving, see Leal 2008.

changes prompting his aggressive behavior
: Stanton 2007 and 2009b found that higher testosterone makes the male amygdala less responsive to fear and more ready to fight in the face of a dominance dominance, testosterone, and Mazur 1998, Archer 2006, Eme 2007, and Carre 2008. challenge. For more on physical aggression, see

emotional events better and longer
: Cahill 2004. Canli 2002 found that women had more brain regions where emotions enhanced memory more powerfully, causing women to remember emotional events better than men.

for memory enhanced by emotion
: Phelps 2004 found that the amygdala and hippocampal complex are linked to two independent memory systems and that in emotional situations, these two systems interact in subtle but important ways.

and activate his territorial fight reaction
: Stanton 2009b. Van Honk 2007 found that in humans a surge of testosterone reduces fear responses and stress-axis reactivity in the brain, altering the natural avoidance of threats by decreasing fear.

their anger harder to control
: Wirth 2007 found that anger in faces was pleasurable and reinforcing to those with higher testosterone. They suggest that testosterone specifically encourages approaching and engaging with angry faces since it is a signal of dominance challenge. Carre 2009 found that changes in testosterone can ignite future aggressive behavior in men.

angry got him fired up
: For more on testosterone fueling aggression, see Stanton 2009b, Wirth 2007, and Archer 2006.

if those feelings are unpleasant
: Tamir 2008 found that individuals may choose to experience emotions that are instrumental (useful), despite short-term hedonic (unpleasant) costs.

people
more
rational, not less
: Tamir 2008. Anger has been claimed to trigger
information processing, but
superficial, nonanalytic

Moons 2007 found that induced anger promoted analytic processing. The study showed that angry people can have both the capacity and motivation to process and think more clearly.

acceptable to express their anger
: For more on males' anger expression, see Dabbs 1996, Mazur 1998, and Archer 2006. Archer 2006 reports that the fear of males in females begins in the first or second grade. Archer 2009 found that sex differences in physical aggression increase with the degree of risk, occur early in life, peak in young adulthood, and are likely to be mediated by greater male impulsiveness and greater female fear of physical danger.

more aggressive than subordinate males
: For more on dominance and subordination in primates, see Wrangham 2004, Sapolsky 1986 and 2005, and Archer 2006.

dominance, thus increasing his testosterone
: For more on dominance challenges, fear, and testosterone, see Van Honk 2001, Hermans 2006, and Josephs 2006. Mehta 2009 found that high-testosterone winners chose to repeat the competitive task, whereas high-testosterone losers chose to avoid it.

by other men but also by women
: Williams 2006 found that there is a perceptual system in both males and females that has evolved to rapidly detect aggression in males and that angry men get noticed more by both sexes. Cox 1999 found that angry men are also judged to be more competent; angry women are judged to be less competent. Roney 2006 found that women have a preference for male faces that indicate higher testosterone.

"you suppressed your anger altogether"
: Harburg 2008 found that a good fight with your spouse may keep you and your marriage healthier.

tendency toward anger and aggression
: Maner 2007 found that men behave differently when the dominance hierarchy is unstable and there is potential for losing their power.

dialed down by social conditions
: Reber 2008 found that subordinate/dominant behavior in an unstable hierarchy influences the hypothalamic production of vasopressin and that subordinate males' exposure to dominants results in diminished body weight and increases anxiety-related behavior. They found that the hormones of aggression in the brains of subordinates decrease after only twenty days.

factors that dial it down
: Burnham 2003 found that testosterone is lower in men who are in stable, committed relationships.

preparing them for turf wars
: Ferris 2008a found that the neural circuitry of aggression and territorial defense can be dialed up with vasopressin.

in his hypothalamus and amygdala
: Ferris 2008a found that the hypothalamus and amygdala help bridge the emotional, motor, and cognitive components of the brain's aggressive responses. The study found that drugs that block vasopressin neurotransmission suppress activity in circuits for aggression and motivation.

is wired into the male brain
: Kozorovitskiy 2004 found that differences in social status correspond to structural differences in the male brain. They found that higher social status accounts for the effect that dominance has on growing new brain cells in the adult male brain.

as they anticipate a confrontation
: For more on rank, aggression, and confrontation in humans and primates, see Mazur 1998, Archer 2006, and Stanton 2009.

opponents within their own species
: For more on male-male fighting and competition, see Motta 2009, Wrangham 2004, and Archer 2006.

circuitry for this instinctive one-upmanship
: Motta 2009 found an area in the male brain's hypothalamus, called the DPN, is activated for instinctive one-upmanship in male rats for territory protection against higher-ranking males.

suited to a luxury sedan
: Mehta 2009 found that men with lower testosterone are more motivated to cooperate with others. Mykletun 2006 found that men in their fifties are more satisfied with their sex lives than men in their thirties and forties. And that men in their fifties recorded similar levels of satisfaction as twenty-to twenty-nine-year-old men.

make less testosterone and vasopressin
: Rosario 2004 and 2009. Geenen 1988 found that young men make more vasopressin than oxytocin due to their high testosterone levels. Debiec 2005 found that oxytocin increases feelings of attachment and love, whereas vasopressin increases feelings of territoriality and defense. Huber 2005 found that vasopressin and oxytocin modulate the brain's circuits for love and fear via their different effects on the amygdala.

increases as men get older
: Rosario 2009 found that in male brains, during normal aging, there was no decrease of estrogen but there was a decrease of testosterone. The ratio of estrogen to testosterone in men thus increased with age. Berchtold 2008 found that clear gender differences in brain aging are evident, indicating that the brain undergoes sex-specific aging changes in gene expression, not only in the developmental period but also in later life.

the cuddling and bonding hormone
: Domes 2007b. Ditzen 2009 found that the effects of increased oxytocin on a couple's relationship could be measured during conflict oxytocin, communication behavior in relation to negative behavior during the couple's conflict discussion. Heinrichs 2008 says that vasopressin has been implicated as a primary factor in male-typical aggressive social behaviors, whereas oxytocin reduces conflict, anxiety, stress, and aggression. Thus relatively more oxytocin and less vasopressin may improve conflict resolution in close relationships.
resolution. When researchers gave more

to read subtle facial expressions
: Domes 2007b found that oxytocin improved the men's performance on a test of the ability to "read the mind" of others from just looking at subtle facial expressions of the eyes and face. Unkelbach 2008 found that oxytocin increases the use of relationship words and language.

more dramatic effect on them
: Juntti 2008 and Jordan 2008. Kosfeld 2005 found that giving young men oxytocin increased their ability to trust others. Fliers 1985 found that with aging, the male brain changes in areas producing vasopressin, especially in brain areas where vasopressin innervation is dependent on higher testosterone levels. Thus as testosterone goes down and estrogen stays the same, the male brain may make not only less vasopressin but more oxytocin, becoming more like the female's.