On monday, johnny's mother gave him cookies and milk after he had played quietly for 10 minutes. on tuesday, she required 20 minutes of quiet play before treat time. on wednesday, she gave him cookies only after he played quietly for a full half hour. johnny was taught to play quietly for extended periods through

shaping

Explanation:

Shaping refers to the action of shaping, creating a pattern of behavior, making it followed by that citizen who wants to behave in a different way than he is used to acting in his daily life.

That's what Johnny's mom is doing. She wants him to adopt the behavior of playing in silence and for that reason, she shapes his behavior by offering rewards whenever he spends a period of time playing in silence.

i believe the answer is true