The Sims 4: Growing Together focuses on the complex bonds between family members and the milestones that shape a Sim's life from infancy to old age. It introduces a "Social Chemistry" system where Sims may naturally click with others or experience friction based on their personality and preferences. Players can experience major life events like midlife crises, sleepovers, and family reunions that have a lasting impact on character traits. The expansion also adds the beautiful suburban world of San Sequoia, designed specifically for multi-generational families to thrive.