Jeff loves to practice the piano. His parents never need to tell him to practice or offer rewards for him to play. Jeff's behavior is best considered an example of:

Why are double-blind studies of medication effectiveness necessary?

a. A placebo is not a treatment. b. If expectancies are too high, treatment might fail. c. Physicians' expectations can influence patients' expectations. d. Patients can't tell if a medication is real.

According to Chess and Thomas, a child who has a low activity level, is somewhat negative, and displays low intensity moods is characterized as

A. uninhibited. B. slow-to-warm-up. C. difficult. D. easy.