Elizabeth B. Hurlock outlines the stages in the lifespan as Prenatal (Fertilization to Birth), Infancy (Birth to 2 weeks of life), Babyhood (2 weeks of life to 2nd year), Early Childhood (2 to 6 years old), Late Childhood (6 to 10 years old), Puberty (10 or 12 to 14 years old), Adolescence (14 to 18 years old), Adulthood (18 to 40 years old), Middle Adulthood (40 to 60 years old), Late Adulthood or Senescence (60 to Death).