Two-Ton, the circus elephant, can balance his whole weight on one of his front legs. What is the likely way in which Two-Ton learned his trick?

A) shaping successive approximations
B) classical conditioning
C) paired associations
D) negative reinforcement

Shaping successive approximations involves gradually training an animal to perform a complex behavior by rewarding closer and closer approximations to the desired behavior. This is likely how Two-Ton learned to balance on one front leg, as it would have been a complex behavior to learn all at once. Classical conditioning, paired associations, and negative reinforcement would not be as effective for teaching this type of behavior.