Marty is a busy father who works long hours and has little time for his son ben. when ben behaves aggressively, marty spends considerable time lecturing him about the inappropriateness of his behavior. ben's aggressive behaviors have increased in frequency for the past few months. how would a behaviorist explain this?

With the increased attention, Marty is positively reinforcing the aggression of Ben.

As Ben is deprived of the attention Marty needs to give, the time Ben gets is just the result of his aggressive behavior which in itself is a kind of reinforcement for Ben to increase in his aggressiveness in order to get more of Marty's time.