JJ has a huge imagination, which is shown sa pamamagitan ng his enthusiasm for magic. With his child-like excitement, he is known to create his own entertaining schemes. JJ is well-spoken and has a vast knowledge in Maths and Science, but he lacks basic social skills due to his high-functioning autism. Because of his disorder, JJ's behaviour can be rather unpredictable and he needs a constant large supply of medications. He is best mga kaibigan with Freddie McLair and James Cook, although in series three, JJ is stuck in the middle when Cook and Freddie fight over Effy. He tries to fix their friendship on many occasions to no avail. He develops a close friendship with Emily Fitch and she allows him to lose his virginity to her as a "one-time charity event". In series four, JJ finds pag-ibig with Lara Lloyd, a single mother and bonds with her baby son, Albert. Through their relationship, JJ discovers a new-found confidence in himself and he begins to doubt whether he really needs to be so highly medicated for his whole life.