Did you noticed that? Here is my "philosophical" interpretation of this magnificent cartoon.
Peter is "Carefree", loves to have fun in the pub, outlandish business with friends, not thinking of anything problematic, good food and resting on the couch watching TV.But he's also "Authority",at the end all revolves around what he does. And when it comes to family and friends, is more than ready to lend a hand, sometimes with incredible steadfastness and affection.
Lois is "Responsibility",is a more attentive parent than Peter, strives to understand the children even when the views are divergent. In addition, it is often her giving inputs to Peter in the decisive moments for their family.But she's also "Pleasure," she cheated on Peter on several occasions, made use of Spinelli and more generally, is aware of her beauty and full of complacency in being courted and coveted as one of the most attractive women in Quahog.
Meg is "Repulsion", no one seems to really appreciate her, is considered wrongly ugly and insignificant, and often people fail to capture the sweetness inside of her. This makes Meg often gray and sad, and this only increases this sense of...