Sibling rivalry

Sibling rivalries are a feature introduced in The Sims 4: Parenthood, where Sims aged toddler to teen have unique interactions with their siblings, ranging from shoving each other whilst angry, arguing with, or teasing each other. Sibling rivalries can be started by having a negative relationship with their sibling, which can be done by doing various mean interactions.

While having a sibling rivalry, both siblings' empathy and conflict resolution character values will decrease. As with usually having a negative relationship, Sims may autonomously do mean interactions towards their rival sibling. Parents can come in and try to fix the siblings bad relationships or they can punish them with grounding or time-outs. When rival siblings age to a young adult, they will gain a permanent relationship with their rival sibling. With a negative relationship they are "Childhood Tormentors", with a positive relationship they are "Thick as Thieves", and with a neutral relationship they are "Family Frenemies".