Psychiatrymiddle twist
A 13-year-old boy is brought by his father because of daily shouting matches at home over the past 18 months. He argues with every request, swears at his parents, deliberately annoys his younger sister and blames her when he is punished. He has never stolen, damaged property or hurt anyone. His teachers describe him as cooperative and his marks are good. He sleeps and eats normally, still enjoys football, and there is no history of trauma or substance use. Which one of the following best accounts for his behaviour?