infants
- develop at a starting rate
neonates
birth - one month
keys to a happy healthy infant
toddlers
ages 1 - 2 years
preschoolers
ages 3 - 5 years
school-age children
ages 6-12 years
adolescents
ages 13- 18 years
early adults
19 - 40 years old
middle adults
41 to 60 years old
late adults
61 and older