“Behavioral science is not for sissies.”

“In behaviorism, an infant's talents and abilities didn't matter because there was no such thing as a talent or an ability. Watson had banned them from psychology, together with other contents of the mind, such as ideas, beliefs, desires, and feelings. They were subjective and unmeasurable, he said, and unfit for science, which studies only objective and measurable things. To a behaviorist, the only legitimate topic for psychology is overt behavior and how it is controlled by the present and past environment. (There is an old joke in psychology: What does a behaviorist say after making love? "It was good for you; how was it for me?")”

“Everyone has a theory of human nature. Everyone has to anticipate the behavior of others, and that means we all need theories about what makes people tick.”

“If we are not to abandon values such as peace and equality, or our commitments to science and truth, then we must pry these values away from claims about our psychological makeup that are vulnerable to being proven false.”

“The task of evolutionary psychology is not to weigh in on human nature, a task better left to others. It is to add the satisfying kind of insight that only science can provide: to connect what we know about human nature with the rest of our knowledge of how the world works, and to explain the largest number of facts with the smallest number of assumptions.”

“Of course genes can’t pull the levers of our behavior directly. But they affect the wiring and workings of the brain, and the brain is the seat of our drives, temperaments and patterns of thought. Each of us is dealt a unique hand of tastes and aptitudes, like curiosity, ambition, empathy, a thirst for novelty or for security, a comfort level with the social or the mechanical or the abstract. Some opportunities we come across click with our constitutions and set us along a path in life.”

“Some people think that evolutionary psychology claims to have discovered that human nature is selfish and wicked. But they are flattering the researchers and anyone who would claim to have discovered the opposite. No one needs a scientist to measure whether humans are prone to knavery. The question has been answered in the history books, the newspapers, the ethnographic record, and the letters to Ann Landers. But people treat it like an open question, as if someday science might discover that it's all a bad dream and we will wake up to find that it is human nature to love one another.”