Researchers compared drinking behaviors of identical twins and fraternal twins who were reared together. Compared to fraternal twins, identical twins were more similar to each other in terms of the amount they drank and whether they became problem drinkers in late adolescence and early adulthood. This finding suggests that _____ play(s) some role in drinking behavior although other factors can also contribute.

a. genes

b. environmental factors

c. epigenetics

d. polygenetic inheritance

Children can begin to think logically once they reach Piaget's ________ stage.

a. concrete operational

b. formal operational

c. preoperational

d. sensorimotor

According to hierarchical models of intelligence, general intelligence "g"

a. is present in all specific factors "s" to the same degree

b. is present in various specific factors "s" to different degrees.

c. is independent of specific factors "s."

Understanding that the past tense of "go" is "went" is a part of

a.phonology.

b. morphology.

c. semantics.

d. syntax.

e. pragmatics.