Final answer:
In 'The Pigman,' Mr. Pignati acts as the primary adult influence who assists John and Lorraine in their maturation process by offering empathy and understanding, marking a significant impact on their journey to adulthood.
Step-by-step explanation:
The adult who helped John and Lorraine the most in their transition from childhood to adulthood in The Pigman by Paul Zindel was Mr. Pignati, also known as the Pigman. As a non-traditional parental figure, Mr. Pignati offers John and Lorraine the empathy, guidance, and understanding they lack from their own families. Rather than judging them, he accepts the teenagers as they are, presenting an adult perspective that is both nurturing and unique. His willingness to be open, share personal feelings, and treat them as equals aids them in realizing the complexities of adult life and relationships. The Pigman's influence encourages the teens to confront the reality of mortality and the consequences of their actions.