ANSWER: CONDUCT DISORDER.
EXPLANATION:
CONDUCT DISORDER (CD) refers to a mental (behavioral and emotional) disorder, that usually begins in childhood or adolescence.
However, this mental disorder is characterised by a repetition and persistence of some certain behaviors, which violates the basic rights or norms of other people.
Children and adolescents with conduct disorder shows aggressive behaviors, destructive behaviors, and deceitful behaviors. These behaviors and either environmentally or genetically induced. Cognitive deficit, learning disability, family and peer influences, are examples of deficiencies seen in individuals with conduct disorder.
Thus, Thomas is seen to be experiencing conduct disorder, because of his history of negative experience in school and with the school management (established his repetitive behaviors), destructive behaviors, aggressiveness, and stealing, which are all considered as ‘antisocial behaviors’.