Early adulthood is a period of life that spans from approximately 18 years (the end of adolescence) until 40 to 45 years (beginning of middle adulthood) . However, some researchers have divided this age period into two separate stages: emerging adulthood followed by early adulthood. Emerging adulthood is the period between the late teens and early twenties, ages 18-25 years, although some researchers have included up to age 29 years in the definition. During this time, individuals have left behind the relative dependency of childhood and adolescence, but have not yet taken on the responsibilities of adulthood. Early adulthood, on the other hand, is generally considered to be the period between ages 18-40. It is a time of peak physical health, and individuals in their twenties and thirties are considered young adults. During this time, individuals experience major life transitions such as leaving the parental home, leaving education, beginning employment, cohabitation, and parenthood.