The 3rd child of the Conner family and was the youngest before his little brother, Jerry Garcia, was born. D.J. is the most gullible, naive, and foolish of all the Conner kids. Many jokes are made towards D.J.. The family teases him alot in the episode, "Homeward Bound" because they discover DJ has started masturbating. He loves to tease and bother his sisters Becky and Darlene.
D.J. tended to be indulged more by Roseanne and Dan, partly because he would not get into serious situations as much as his older sisters and had a less argumenative personality; however, he is nonetheless a very mischevious child, and well-versed in the art of blackmail. This is sometimes tolerated by his parents, who like to preserve his innocence when their lives become difficult, but not by his sisters, who are shown to (for the most part) despise him.
Becky would often babysit her little brother and indulged him somewhat in early seasons, but as she focused more on her romantic life and career she saw him more as a distraction and a nousance, a belief that his actions did little to counter. After she eloped with Mark, there was little connection between her and D.J., although he greeted her happily the first time she came back.
Darlene, on the other hand, would retaliate physically when D.J. pulled some trick on her or otherwise irritated her; Roseanne reminisced in one episode of how Darlene had dented the wall with D.J.'s head 'to mark how tall he's getting'. Despite being intimidated by his middle sister, D.J. continued his attempts to annoy her for most of the series. However, when he visited her at college, he honestly told her that he missed her; on some occasions, Darlene and D.J. were shown working together very effectively against either Roseanne or Becky.
As for the Healys, D.J. definitely looked more towards Mark, despite his lack of intelligence. He dismissed David as effeminate and overly- emotional on many occasions. In Season 9, D.J. starts developing a definite interest in film-making, as evidenced by his various posters of Spielberg films, his desire to film Darlene giving birth (although he fainted repeatedly when watching another birth video as practice) and his making a stop-motion clay-animated film; in the finale, when he moves into David's old space in the basement, Roseanne encourages his idea of turning it into a miniature studio.