Alcohol and cigarettes feature prominently in The Pigman. Drinking alcohol is an escape for John – an escape from school, from responsibility – but it is not a way of defying his parents. His father actually encouraged John to drink alcohol when John was about ten years old. John also smokes a lot and Lorraine has been unsuccessful in her efforts to get him to stop.
John drinks to escape the realities of his life.
The adults in the novel who give alcohol to minors [John's father; Mr. Pignati; Tony, who sells kids beer (6)] are partially responsible for the minors' alcohol abuse.