Conception – 3 months Prenatal & Newborn From fertilisation through the first three months of life — organ formation, brain development, and the foundations of early attachment.
26 milestones →
3–12 months Infancy Motor control, object permanence, and attachment all emerge. The infant learns by acting on the world.
27 milestones →
1–3 years Toddler Language acquisition accelerates dramatically. Symbolic thought and self-recognition emerge. Erikson's Autonomy vs. Shame & Doubt.
31 milestones →
3–5 years Preschool Piaget's preoperational stage. Theory of mind emerges around age 4. Erikson's Initiative vs. Guilt.
18 milestones →
5–7 years Early School Age Concrete operational thinking begins. School introduces structured learning, peer comparison, and Industry vs. Inferiority.
17 milestones →
7–11 years Middle Childhood Logical and systematic thinking develops. Complex peer networks form. Metacognition and memory strategies emerge.
17 milestones →
11–14 years Early Adolescence Puberty and abstract reasoning begin. Identity vs. Role Confusion. Peers replace parents as the primary social reference group.
14 milestones →
14–18 years Late Adolescence Identity consolidates. Prefrontal cortex matures further. Intimate relationships deepen and future planning intensifies.
14 milestones →