Answer:
-John B. Watson and B. F. Skinner.
Step-by-step explanation:
John B. Watson: He is known for theorizing behaviorism and hence implementing it to the child development. According to him, an individual's (child) environment is responsible for shaping his or her behavior rather than the genetics and natural temperament.
B. F. Skinner: He believed the idea of behaviorism and has developed or introduced operant conditioning theory. According to him, an individual's behavior is determined by various consequences including punishments and reinforcements.