A clinical psychologist assessing the intelligence of an 8-year-old client with a Wechsler test should use the

Piaget's theory of intellectual development assumes that:

a. children pass through certain stages at a specific age. b. children pass through a series of 6 sequential stages. c. children pass through a series of stages in the same order. d. children pass through stages but in no particular order and at no specified ages.

The chemicals responsible for such things as differences in vitality among people, rates of metabolism, sexual development, preparation for pregnancy and childbirth, and emotional balances in general are called ______

a. neurotransmitters b. hormones c. antigens d. enzymes