How many variables are required to calculate a correlation coefficient?

Exposure to teratogens during __________ is most likely to produce major defects in bodily structure

a. conception c. the period of the zygote b. the period of the fetus d. the period of the embryo

Purging is ______ because it produces relief from anxiety over gaining weight

a. classically conditioned c. modeled b. positively reinforced d. negatively reinforced