Answer:
In this example, whose behavior has been shaped? His mom's behavior has been shaped.
Step-by-step explanation:
Shaping one's behavior concerns offering reinforcements to successive approximations. In this particular case, Tommy first reinforced his mom's yelling. That is, he only did what she wanted when she yelled at him. Therefore, he has "taught" her to yell to get him to do what she wants. Then, he began to ignore her until she had yelled more than once. That went on to the point of her yelling 10 times. Tommy is clearly manipulating his mother by shaping her behavior. First he made her yell, now he makes her yell 10 times. He will probably keep on doing that until he can get her to give up on having him stop playing video games.