The chapter discusses the social and emotional aspects of aging, highlighting how these processes contribute to well-being across the adult lifespan. Despite biological and physiological declines, older adults generally report high levels of emotional well-being and satisfaction. The shift from unidimensional decline models to lifespan developmental models has been driven by the contrast between physical and psychological changes. Social and emotional functioning remains stable, but changes occur in the nature of social networks and emotional experiences. Strong social networks are associated with better cognitive functioning, physical health, and emotional well-being. Emotional well-being is characterized by a higher level of positive affect and lower levels of negative affect, which are maintained or even increased with age. Theories such as Selective Optimization with Compensation (SOC) and Socioemotional Selectivity Theory (SST) explain how older adults prioritize emotionally meaningful relationships and adapt their perspectives to focus on positive experiences. Age-related changes in appraisals, memory, and behavioral responses contribute to these positive outcomes. Despite biological declines, older adults tend to experience less distress and have more positive appraisals and memories, leading to higher levels of well-being. However, the chapter also acknowledges the challenges and vulnerabilities associated with aging, such as the increased risk of negative social exchanges and the impact of unavoidable stressors. Overall, the chapter emphasizes the importance of understanding the interactions between social and emotional processes and biological systems to fully grasp the aging experience.The chapter discusses the social and emotional aspects of aging, highlighting how these processes contribute to well-being across the adult lifespan. Despite biological and physiological declines, older adults generally report high levels of emotional well-being and satisfaction. The shift from unidimensional decline models to lifespan developmental models has been driven by the contrast between physical and psychological changes. Social and emotional functioning remains stable, but changes occur in the nature of social networks and emotional experiences. Strong social networks are associated with better cognitive functioning, physical health, and emotional well-being. Emotional well-being is characterized by a higher level of positive affect and lower levels of negative affect, which are maintained or even increased with age. Theories such as Selective Optimization with Compensation (SOC) and Socioemotional Selectivity Theory (SST) explain how older adults prioritize emotionally meaningful relationships and adapt their perspectives to focus on positive experiences. Age-related changes in appraisals, memory, and behavioral responses contribute to these positive outcomes. Despite biological declines, older adults tend to experience less distress and have more positive appraisals and memories, leading to higher levels of well-being. However, the chapter also acknowledges the challenges and vulnerabilities associated with aging, such as the increased risk of negative social exchanges and the impact of unavoidable stressors. Overall, the chapter emphasizes the importance of understanding the interactions between social and emotional processes and biological systems to fully grasp the aging experience.