Piaget
1896–1980 · SwitzerlandCognitive stages
Piaget shaped discourse on identity and emerging autonomy through research and public writing.
Teenager drew researchers from psychology, paediatrics, education, and anthropology.
Eight influential figures below span theory, clinical work, and global policy.
Eight guides worth knowing
William Sears
b. 1939 · USAttachment parenting
William Sears shaped discourse on identity and emerging autonomy through research and public writing.
Penelope Leach
b. 1937 · UKPractical child development
Penelope Leach shaped discourse on identity and emerging autonomy through research and public writing.
Montessori
1870–1952 · ItalyPrepared environment
Montessori shaped discourse on identity and emerging autonomy through research and public writing.
Ellyn Satter
b. 1942 · USFeeding dynamics
Ellyn Satter shaped discourse on identity and emerging autonomy through research and public writing.
T. Berry Brazelton
1918–2018 · USInfant cues
T. Berry Brazelton shaped discourse on identity and emerging autonomy through research and public writing.
Erikson
1902–1994 · Germany/USPsychosocial stages
Erikson shaped discourse on identity and emerging autonomy through research and public writing.
Judy Dunn
b. 1940 · UKSibling relationships
Judy Dunn shaped discourse on identity and emerging autonomy through research and public writing.
Together they moved teenager from opinion columns toward evidence-informed frameworks still debated today.
Keep exploring
More in Developmental stages
👶
Newborn
The first 28 days after birth — physiology, bonding, feeding rhythms, and the shift from womb to world.
Evidence 88 🍼Infant
From one month to twelve months — motor milestones, first foods, attachment deepening, and emerging sleep patterns.
Evidence 90 🧸Toddler
Walking, talking, and testing limits — the toddler years blend motor explosion, language bursts, and autonomy struggles.
Evidence 85 ✏️Preschool
Imaginative play, peer entry, and executive function growth define the preschool years before formal schooling.
Evidence 82 📚School Age
Industry, friendships, and academic skill-building mark middle childhood between toddler chaos and adolescent identity work.
Evidence 78