Topic
Development & Milestones — Pillar Guide
All of Development & Milestones, organized by age stage.
By age stage
Pregnancy & Newborn
last trimester – 3 mo
Infant
3 – 12 mo
Toddler
1 – 3 yr
Preschool
3 – 5 yr
Early School-Age
5 – 8 yr
Tween
8 – 12 yr
Teen
13 – 17 yr
All articles in this topic
Understanding the Brain's Blueprint: How Cognitive Development Actually Works
Everyday play, conversation, and hands-on exploration are the most powerful drivers of cognitive development in children aged 0–12 — and parents are the single biggest factor in making that happen.