the study of ...?

Question

why do we do the things we do? why do we act the way we act? why do we think in the way we do? i'm trying to find what branch of psychology those questions would be answered under.

Answer 1

Sociology - it's all about the culture.
If you were born and raised as a native in New Zealand you may have been a cannibal. To that society eating your dead enemy "A human" was a normal and accepted way of life.
to the rest of the worlds cultures eating people is not normal or acccepted.
It is all about how your society lives that makes you do what you do.

:o)
Jerry

Answer 2

Evolutionary psychology. There is a very good book by Robert Wright addressing this subject called The Moral Animal: Why We Are, the Way We Are: The New Science of Evolutionary Psychology

Here is a review from the Amazon website for this book:

Although first published in 1994, a long time ago in the rapidly developing science of evolutionary psychology, Robert Wright's seminal book remains an excellent introduction to the subject. The text crackles with an incisive wit that says, yes we're animals, but we can live with that. The discussion is thorough, ranging from a rather intense focus on Charles Darwin and his life through the sexist and morality debate occasioned by the publication of Edward O. Wilson's Sociobiology in 1975, to the rise of the use of primate comparisons fueled by Jane Goodall's instant classic, The Chimpanzees of Gombe: Patterns of Behavior (1986). Wright has some rather serious fun with human sexual behavior as seen from the perspective of evolutionary psychology, but he spends even more time worrying (to no good effect, in my opinion) about altruism and the shaky concept of kin selection. The title is partly ironic, since much of the material suggests that we are something less than "moral." The "Everyday Life" in the title is an allusion to Freud (The Psychopathology of Everyday Life, 1904) who makes a dual appearance in the text, first as a kind of not-yet-illuminated precursor to modern Darwinian thought, and second as the reigning champ of psychology that evolutionary psychology is out to dethrone. (See especially page 314.)

Answer 3

Evolutionary psychology. Remember that it is still psychology; thus lacking rigor.