______ grandparents entertain and "spoil" their grandchildren

A source of bias that may explain racial IQ differences is the fact that most IQ tests rely heavily on

a. math skills. b. vocabulary level. c. the ability to pay attention. d. individual responsibility. e. interpersonal intelligence.

A researcher conducts a two-way within-subjects factorial experimental design in which one factor had two levels. If 60 total participants were observed in each group, then the second factor must have how many levels?

A. two B. four C. six D. not enough information