_____ alerts us to the dangers in the environment preparing us to deal with stress.

Compared to the past, girls in the United States experience ___________ at the significantly younger age of 11 or 12, most likely because of better nutrition and overall health

a. adolescence c. growth spurts b. puberty d. menarche

You have designed an experiment to test a new drug. You prepare the injection doses of the drug and a placebo and label them with different alphabet letters. Then, you hire research assistants to give the injections and to collect data from the participants. These research assistants as well as the participants will not know which injection is the drug or which is the placebo or whether a

participant is in the experimental or the control group. You have a. created a placebo effect. b. designed a single-blind experiment. c. designed a double-blind experiment. d. created a self-fulfilling prophecy.