Physical and cognitive changes occur in middle adulthood from 40-50 years old. Visible signs of aging like wrinkles and gray hair emerge, and chronic health issues become more common. Sleep problems increase and memory begins to slowly decline, though expertise grows from years of experience. Socioemotional development involves reassessing relationships and roles. While divorce is possible, affectionate love in marriages tends to increase. The empty nest period after children leave home can impact marital satisfaction but opens up new interests and time for couples.