Between the ages of 18 and 24 months toddlers have learned and use two notable words. What are they?

The tendency to complete figures that are incomplete is known as __________

a) figure–ground relationship. b) closure. c) similarity. d) continuity.

Karin's mother took her into a rest room at Disney World. The loud and powerful flushing caused Karin to cry. When she and her parents returned home, they found that Karin would not go near the potty chair they were using for toilet training. They concluded that Karin developed a phobia as a result of

a) learned helplessness. b) operant conditioning. c) classical conditioning. d) vicarious conditioning.