.The typical age of attaining legal adulthood is 18, although the definition may

.The typical age of attaining legal adulthood is 18, although the definition may vary by legal rights, country, and psychological development. Human adulthood encompasses psychological adult development. Adulthood is divided into three stages: (1) early, (2) middle, and (3) late adulthood. Early adulthood starts at age 18 or 21 and continues until the mid-30s. During middle adulthood, people begin to show signs of aging. Late adulthood is when most people retire from work and reflect on their life. Physical changes in early adulthood include reaching full height and weight, muscle gains, and a slight increase in body fat. Early adults also peak in physiological functioning as they experience increased muscle strength, reaction time, agility, bone density, and cardiac functioning.The typical age of attaining legal adulthood is 18, although the definition may vary by legal rights, country, and psychological development. Human adulthood encompasses psychological adult development. Adulthood is divided into three stages: (1) early, (2) middle, and (3) late adulthood. Early adulthood starts at age 18 or 21 and continues until the mid-30s. During middle adulthood, people begin to show signs of aging. Late adulthood is when most people retire from work and reflect on their life. Physical changes in early adulthood include reaching full height and weight, muscle gains, and a slight increase in body fat. Early adults also peak in physiological functioning as they experience increased muscle strength, reaction time, agility, bone density, and cardiac functioning.