When an investigator devises different conditions and then compares the outcomes of the participants exposed to those different conditions in order to see how behavior is affected, what is this is called?

The second phase of the sexual response is __________

a) excitement. b) plateau. c) orgasm. d) resolution.

Which of the following statements is true about the effects of lead exposure in childhood?

A) A stressed, disorganized home life seems to heighten lead-induced damage. B) Investigators agree that the greatest period of vulnerability is middle childhood. C) Children given drugs to induce excretion of lead (chelation) improve dramatically. D) Negative cognitive consequences are not evident when the level of lead exposure is below 10 µg/dL.