According to Jim COMPLETE S 1-8
Jim is an abrasive but lovable suburban father. Much like his real life counterpart, Jim’s character is noted as a fan of blues music, as well as the Chicago Bears, Chicago Cubs, Chicago Bulls and the Chicago Blackhawks. Together with his wife Cheryl, whose middle name is Mabel, they have three children, daughters Ruby and Gracie and son Kyle. In the seventh season they become parents of a pair of twins Jonathan and Gordon.
Jim often finds himself in messy situations because his laziness inclines him to search for alternative ways of doing things with least effort. While Cheryl’s brother Andy may be Jim’s best friend, her sister Dana frequently teams up with Cheryl against Jim. He also prefers to lie to Cheryl and Dana to do his own activities but they end up backfiring on him. He hates losing to women (e.g. Hot Dog Eating Contests, Hamburger Eating Contests, Pizza Eating Contests, Pot Pie Eating Contests), especially if Cheryl or Dana find out. He doesn’t like people interrupting him when he talks, so he speaks over them to shut them up. Jim often makes an example of Andy, who doesn’t have a girlfriend.