Justin "follows faithfully in his father's footsteps", dreaming of a career in athletics and sports. He is also extremely outgoing, like his parents and Amar, and knows most of the other kids in the neighbourhood by name. However, he isn't friends with all of them yet. While Justin tends to get along well with other children, the fact that he lives in the wealthiest household in the neighbourhood (and county, and possibly the rest of the state) creates a large class divide that is very visible when Justin visits the apartment of a poorer Sim. Justin, however, is unwilling to leave the lavish comforts of his wealthy life, and would rather stay at home than visit a poorer kid's flat.
Despite this shortcoming, Justin is generally well liked. He has gold talent badges in both gardening and fishing — both learned from the time he spent with Chase — and shares in his parents' interest to befriend as many people as possible for the most part.
Justin has a memory of teaching his younger brother Evan a nursery rhyme when he was a toddler.
Interestingly, despite only being a child, Justin has five permanent want slots instead of the usual four. This is not possible without the use of cheats.