Final answer:
The parent is using positive reinforcement to discourage aggression in their child.
Step-by-step explanation:
The parent is using a positive reinforcement method to discourage aggression in their child. Positive reinforcement involves adding a desirable stimulus to increase a behavior. By reinforcing playing nicely, doing homework, being pleasant, and taking the dog for walks, the parent is increasing the likelihood that the child will continue to exhibit these positive behaviors.