The social psychologist fritz heider is historically important in the field for his contribution of
a. cross-cultural research.
b. the six universal facial expressions.
c. the covariation model.
d. attribution theory.

"choosing is refusing" means individuals face an opportunity cost with each decision they make. economists state that every decision involves trade-offs. opportunity cost is the least desirable alternative given up as a result of a decision.

answer; validity;

answer; ///biological psychologists;

answer; acquired mainly during early childhood;