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November 11, 2017 - January 9, 2018
where “left brain”–edness has the connotation of anal-retentive bean counting and “right brain”–edness is about making mandalas or singing with whales. In fact the functional differences between the hemispheres are generally subtle, and I’m mostly ignoring lateralization.
And I don’t mean scientists not saying hello to each other at conferences. I mean a major public shit storm.
Moreover, the amygdala expands in size with long-term PTSD.
The frontal cortex is the last brain region to fully mature, with the most evolutionarily recent subparts the very last. Amazingly, it’s not fully online until people are in their midtwenties. You’d better bet this
actor lies to an audience about having the feelings of a morose Danish prince.
Punishing norm violations is satisfying.
Why? This is our world of habituation, where nothing is ever as good as that first time.
After all, reward coding must accommodate the rewarding properties of both solving a math problem and having an orgasm.
This was shown in a beautiful study by Wolfram Schultz of Cambridge University.87 Depending on the circumstance, monkeys were trained to expect either two or twenty units of reward. If they unexpectedly got either four or forty units, respectively, there’d be an identical burst of dopamine release; giving one or ten units produced an identical decrease.
An emptiness comes from this combination of over-the-top nonnatural sources of reward and the inevitability of habituation; this is because unnaturally strong explosions of synthetic experience and sensation and pleasure evoke unnaturally strong degrees of habituation.
If we were designed by engineers, as we consumed more, we’d desire less. But our frequent human tragedy is that the more we consume, the hungrier we get.
Dopamine is about mastery and expectation and confidence. It’s “I know how things work; this is going to be great.” In other words, the pleasure is in the anticipation of reward, and the reward itself is nearly an afterthought (unless, of course, the reward fails to arrive, in which case it’s the most important thing in the world).
This explains context-dependent craving in addiction.93 Suppose an alcoholic has been clean and sober for years. Return him to where the alcohol consumption used to occur (e.g., that rundown street corner, that fancy men’s club), and those potentiated synapses, those cues that were learned to be associated with alcohol, come roaring back into action, dopamine surges with anticipation, and the craving inundates.
that signals that some kind of reward is likely, without knowing what or when. This is what fetishes
Remarkably, once that new scenario is learned, far more dopamine is released. Why? Because nothing fuels dopamine release like the “maybe” of intermittent reinforcement.95
Subjects guess political affiliation or religion at above-chance levels just by looking at faces.
Eyes give the most information.20 Take pictures of two faces with different emotions, and switch different facial parts between the two with cutting and pasting. What emotion is detected? The one in the eyes.
complex background. Within seconds, people from collectivist cultures (e.g., China) tend to look more at, and
Most important, the rise in testosterone after a challenge makes aggression more likely.17 Think about this. Testosterone levels rise, reaching the brain. If this occurs because someone is challenging you, you head in the direction of aggression. If an identical rise occurs because days are lengthening and mating season is approaching, you decide to fly a thousand miles to your breeding grounds. And if the same occurs because of puberty, you get stupid and giggly around that girl who plays clarinet in the band. The context dependency is remarkable.
Heterosexual male volunteers, with or without an oxytocin spritz, interacted with an attractive female researcher, doing some nonsense task.
(Why didn’t oxytocin make them stand closer? The researchers indicated that they were already about as close as one could get away with.)
Now for something truly charming that evolution has cooked up recently. Sometime in the last fifty thousand years (i.e., less than 0.1 percent of the time that oxytocin has existed), the brains of humans and domesticated wolves evolved a new response to oxytocin: when a dog and its owner (but not a stranger) interact, they secrete oxytocin.
Both female baboons and female vervet monkeys become more aggressive and less social before their menses (without, to my knowledge, having issues with American capitalism).
You’ve got your maximal number of neurons around birth, and it’s downhill from there, thanks to aging and imprudence.
You see where we’re heading—adult brains, including aged human brains, do make new neurons. The finding is truly revolutionary, its discovery epic. In 1965 an untenured associate professor at MIT named Joseph Altman (along with a longtime collaborator, Gopal Das) found the first evidence for adult neurogenesis, using a then-novel technique.
Hippocampal neurogenesis, for example, is enhanced by learning, exercise, estrogen, antidepressants, environmental enrichment, and brain injuryfn9 and inhibited by various stressors.
This is when you learn that two things you previously thought were the same are, in fact, different—dolphins and porpoises, baking soda and baking powder, Zooey Deschanel and Katy Perry.
As we’ll see, neurobiology suggests that adolescence is for real, that the adolescent brain is not merely a half-cooked adult brain or a child’s brain left unrefrigerated for too long.
For example, adolescents are not at adult levels of competence at detecting irony and, when trying to do so, activate the dmPFC more than do adults.
Reappraisal strategies get better during adolescence,
IN THE FOOTHILLS of the Sierras are California Caverns, a cave system that leads, after an initial narrow, twisting 30-foot descent down a hole, to an abrupt 180-foot drop (now navigable by rappelling). The Park Service has found skeletons at the bottom dating back centuries, explorers who took one step too far in the gloom. And the skeletons are always those of adolescents.
Feeling someone else’s pain is painful, and people who do so most strongly, with the most pronounced arousal and anxiety, are actually less likely to act prosocially. Instead the personal distress induces a self-focus that prompts avoidance—“This is too awful; I can’t stay here any longer.” As empathic pain increases, your own pain becomes your primary concern.
As has been said, the greatest crime-fighting tool is a thirtieth birthday.
They’re less likely to be left-handed (a male-skewed trait).
Childhood abuse, for example, causes epigenetic changes in hundreds of genes in the human hippocampus.
most effects of childhood experience on adult outcomes probably don’t involve epigenetics and (stay tuned) most epigenetic changes are transient.
Collectively, the research consistently showed that genetics plays a major role in a gamut of domains of behavior, including IQ and its subcomponents (i.e., verbal ability, and spatial ability),fn11,15 schizophrenia, depression, bipolar disorder, autism, attention-deficit disorder, compulsive gambling, and alcoholism.
Nearly as strong genetic influences were shown for personality measures related to extroversion, agreeableness, conscientiousness, neuroticism, and openness to experience (known as the “Big Five” personality traits).16 Likewise with genetic influences on degree of religiosity, attitude toward authority, attitude toward homosexuality,fn12 and propensities toward cooperation and risk taking in games. Other twin studies showed genetic influences on the likelihood of risky sexual behavior and on people’s degree of attraction to secondary sexual characteristics (e.g., musculature in men, breast
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Or how about the link between genes and self-confidence? Some studies show that the intervening variable is genetic effects on height; taller people are considered more attractive and treated better, boosting their self-confidence, dammit.
Current research actively explores gene/environment interactions.37 How’s this for fascinating: Heritability of various aspects of cognitive development is very high (e.g., around 70 percent for IQ) in kids from high–socioeconomic status (SES) families but is only around 10 percent in low-SES kids.
In other words, genes are nearly irrelevant to cognitive development if you’re growing up in awful poverty—poverty’s adverse effects trump the genetics.fn24
Amazingly, prison sentences for murderers have now been lessened in at least two cases because it was argued that the criminal, having the “warrior gene” variant of MAO-A, was inevitably fated to be uncontrollably violent. OMG.
What does having a particular variant of the MAO-A gene have to do with antisocial behavior? It depends on the environment. “Warrior gene” my ass.
Consider a classic GWAS that looked for genes related to height. This was a crazy difficult study involving examining the genomes of 183,727 people. 183,727. It must have taken an army of scientists just to label the test tubes. And reflecting that, the paper reporting the findings in Nature had approximately 280 authors.
over the course of millennia, earlier adoption of the hoe over the plow predicts gender equality today.2
Then there’s the Philippines, where 93 percent of people say they feel happy and loved, versus 29 percent of Armenians.
in rural Kentucky in the 1940s, for example, 70 percent of men had the same first name as their father, far more than in the North.
Hatfields and McCoys famously began their nearly thirty-year feud in 1863,
There were the Pilgrims from East Anglia in New England. Quakers from North Midlands going to Pennsylvania and Delaware. Southern English indentured servants to Virginia. And the rest of the South? Disproportionately herders from Scotland, Ireland, and northern England.
According to estimates by the UN and advocacy groups, five to twenty thousand honor killings occur annually. And they are not restricted to far-off, alien lands. Instead they occur throughout the West, where patriarchs expect their daughters to be untouched by the world they moved them to, where a daughter’s successful assimilation into this world proclaims the irrelevance of that patriarch.
