Quotes About Biology

A chicken is an egg's way of making another egg

The candidate gene approaches show that the effect of a single gene on a behavior is typically tiny. In other words, having the "warrior gene" variant of MAO probably has less effect on your behavior than does believing that you have it.

The biologies of strong love and strong hate are similar in many ways, as we'll see.

When deontologism and consequentialism contemplate trolleys, the former is about moral intuitions rooted in the vmPFC, amygdala, and insula, while the latter is the domain of the dlPFC and moral reasoning. Why is it that our automatic, intuitive moral judgments tend to be nonutilitarian? Because, as Greene states in his book, "Our moral brains evolved to help us spread our genes, not to maximize our collective happiness.

you can't begin to understand things like aggression, competition, cooperation, and empathy without biology; I say this for the benefit of a certain breed of social scientist who finds biology to be irrelevant and a bit ideologically suspect when thinking about human social behavior.

by the time you finish this book, you'll see that it actually makes no sense to distinguish between aspects of a behavior that are "biological" and those that would be described as, say, "psychological" or "cultural." Utterly intertwined.

I can't really imagine how to live your life as if there is no free will. It may never be possible to view ourselves as the sum of our biology. Perhaps we'll have to settle for making sure our homuncular myths are benign, and save the heavy lifting of truly thinking rationally for where it matters—when we judge others harshly.

willpower takes metabolic power, thanks to the glucose demands of the frontal cortex. This was the finding that when people are hungry, they become less generous in economic games.

The human olfactory system is atrophied; roughly 40 percent of a rat's brain is devoted to olfactory processing, versus 3 percent in us.

So oxytocin is central to female mammals nursing, wanting to nurse their child, and remembering which one is their child.

University of Cambridge.68 When compared with non-CAH girls, CAH girls do more rough-and-tumble play, fighting, and physical aggression. Moreover, they prefer "masculine" toys over dolls. As adults they score lower on measures of tenderness and higher in aggressiveness and self-report more aggression and less interest in infants. In addition, CAH women are more likely to be gay or bisexual or have a transgender sexual identity.

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.

evolution is about reproduction, passing on copies of genes.

no se puede empezar a comprender algo como la agresividad, la competencia, la cooperación y la empatía sin la biología;

Cuando haya acabado de leer este libro, verá que, al hablar de los distintos aspectos de un comportamiento, no tiene sentido distinguir entre los que son «biológicos» y aquellos que podrían ser descritos por ejemplo como «psicológicos» o «culturales». Están totalmente entrelazados.

The picture is complicated further—AIS individuals raised female have higher-than-expected rates of being gay, and of having an other-than-female or neither-female-nor-male-sex/gender self-identification.

What's a heritability score? "What does a gene do?" is at least two questions. How does a gene influence average levels of a trait? How does a gene influence variation among people in levels of that trait?

These are crucially different. For example, how much do genes have to do with people's scores averaging 100 on this thing called an IQ test? Then how much do genes have to do with one person scoring higher than another?

the fetal brain generates far more neurons than are found in the adult.

Robert M. Sapolsky

Thus, oxytocin and vasopressin facilitate bonding between parent and child and between couples.fn10 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.

If genes strongly influence average levels of a trait, that trait is strongly inherited. If genes strongly influence the extent of variability around that average level, that trait has high heritability.

And you'd better bet that changes along the lines of those presented in this chapter occurred in the brains of anyone transformed by these transformations. A different world makes for a different worldview, which means a different brain. And the more tangible and real the neurobiology underlying such change seems, the easier it is to imagine that it can happen again.

While average finger number is an inherited trait, the heritability of finger number is low—genes don't explain individual differences much.