Kelsey, age 10, is impulsive. during school, he drops his pencil, rearranges the papers inside his desk, and yells at people across the room. kelsey fails to follow the rules when he plays games and lashes out with hostility when he is frustrated. he suffers from both academic and social problems. kelsey most likely has

I am not 100% sure about my answer, so don't hate me if i get it wrong, but I think that Kelsey has Obsessive-Compulsive Disorder

My explanation - Obsessive-Compulsive Disorder (OCD) is a common, chronic and long-lasting disorder in which a person has uncontrollable, reoccurring thoughts (obsessions) and behaviors (compulsions) that he or she feels the urge to repeat over and over.

prolly ocd alot of people might do that so prolly ocd

Explanation:

because the early people found out about it.