In his research into the personality traits of animals, Samuel Gosling found that ________ are the most similar to human beings

Charles Darwin's __________ emphasized two related principles: natural selection and survival of the fittest

A) normative approach B) theory of evolution C) psychoanalytic theory D) psychosocial theory

Whereas ________ research methods allow us to show how one variable produced a change in

another variable, ________ research methods cannot support cause-and-effect conclusions. A) experimental; descriptive B) independent; dependent C) valid; invalid D) descriptive; experimental