Top Quotes “The Happy Brain: The Science of Where Happiness Comes From, and Why” — Dean Burnett

The Brain’s Rewards

“Dopamine release is affected by how surprising a reward or experience is. The more unexpected something is, the more we enjoy it. Expected rewards correspond with an initial dopamine surge, which then tails off. But unexpected rewards correspond with an increased level of dopamine release for a longer period after the reward is experienced. This is why finding a $20 bill in your pocket is more exciting than your bi-weekly paycheck.”

The Social Brain

“Human social groups got so successful that the usual ecological processes driving evolution no longer applied; if you’re part of a human community, you’re protected from things like predators and have ready access to food, safety, mates, etc. So succeeding in the environment was less successful than succeeding in the community. Survival of the fittest now means survival of the most likable, friendly individuals, able to benefit the group with ideas and innovations like tools and agriculture. These individuals were the ones who succeeded, got to spread their genes. But all those things require greater intelligence. Several hundred thousand years later, here we are.” “If you give a chimp a banana, it’ll focus on the banana. ‘A banana. I like bananas. I’ll eat that.’ If you give a human a banana, they’ll focus on you. “Why’s this person giving me a banana? What do they want?’ This is what happens when a species evolves according to social rather than environmental pressures. If your survival depends on your community, the more social you are, the greater your chances of acceptance and survival.”

Sex & Love

“Certain body types tend to be more arousing than others. Rippling abs, curvy hips, sensual full lips, big muscles; these tend to get us more ‘fired up’ than a glimpse of an earlobe or elbow. The reason for this is that they’re considered ‘secondary sex characteristics,’ features that evolved to attract mates, but aren’t part of the reproductive process.”


“Laughter is also found in primates like chimpanzees, but theirs sounds different from ours — more like ‘frantically sawing through a wooden plank.’ These different types of laughter diverged from a common ancestor species, between 10 and 16 million years ago. Far from being uniquely human, laughter is maybe four times older than humanity itself!

The Unique You

“Some influences are persistent and enduring, effectively ‘loading the dice’ in favor of an outcome; you grow up in a very musical family, you’ll be surrounded by music all the time, so will probably have strong feelings about music — love it or hate it. Other influences, while temporary, can be incredibly powerful and engage many areas of the brain in significant ways, such as your first sexual encounter. Someone whose first sexual experience is with a redhead way well end up persistently attracted to redheads. The brain is quick to learn novel things with highly stimulating, emotional properties, so in this instance the basic learning processes rapidly make a “redheads = sexual pleasure” association. The brain is good at generalizing here; it doesn’t have to be the exact same redhead each time, because similar stimuli can produce a similar reaction, resulting in an overall fondness for things that have preferred elements in common. That’s why we like certain bands, or styles of music, or genres of film, rather than just one specific example that we first discovered and enjoyed. This does mean that if someone likes something you hate, then there’s a great chance of them liking other things that you are more likely to dislike. Differences between you become wider and wider.

“Positive” Biases

Due to an optimism bias, we tend to assume a best-case scenario is the most likely outcome, based on nothing more than baseless assumptions. In many ways, this is actually helpful; a positive outlook is reliably linked to improved mental well-being and tolerance of stressful events, and can help with motivation and goals. On the other hand, assuming things will turn out fine can be unhelpful, even self-defeating. ‘I could avoid getting lung cancer by quitting smoking, but I’ll probably not get it anyway, so why bother?’— and then you get lung cancer. See how that works?”

From Childhood to Old Age

“When evolution awarded us more brainpower, this required bigger heads and skulls. Butt his growth was localized to our heads; our body size is consistent with primate averages. As a result, our heads grow ‘faster’ than the rest of our bodies. A baby’s body is about 5 percent of its eventual adult size, but its head is around 25 percent. Because the dimensions of the birth canal are restricted by the width of the sold bone female pelvis, babies need to be born while their delicate heads still fit through it. But because evolution has caused our heads to develop at an increased rate, our bodies aren’t as fully developed as they ‘should’ be when they emerge into the world. Babies are born at a much earlier stage of physical development than most other species. This could explain why children can learn so much and are so sensitive to what is around them in their first year of life.



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