Developmental Milestones

The Developmental Milestones Study

The Infant Developmental Milestones Study

This is an ongoing longitudinal study of more than 550

• infants and babies
  
• toddlers, and
• preschoolers.

Parents complete daily parent checklists to identify the ages when children reach key development milestones like

• sitting,
• crawling, and
• walking.

Other infancy abilities are measured and include

• joint attention
• deferred imitation
• size (weight, length, head circumference)

At two years, participants are assessed on language and cognitive ability measures.

Funded by the Social Sciences and Humanities Research Council of Canada.

• Kids vary in rate of development through milestones like sitting, walking, talking, and puberty
• Little is known about what causes the variability in rates
• Good descriptions of their paths (developmental trajectories) are needed but are virtually non-existent
• We use Milestone Age by plotting ages of attainment for near-universal milestones like sitting, crawling, and walking

Milestone age is plotted above for two infants, one advanced (A) and one delayed (B) The dotted line is the trajectory for a baby who attained all milestones at the 50th percentile, and the bars along the vertical axis indicate the median ages for various milestones.

More details about the Milestone Study