Youth health behavior decline mapped across 7 developmental stages (P3–JC/Poly/ITE) with ecosystem influences, evidence, and research gaps. Bookend stages (P3–P4, JC/Poly/ITE) are directional estimates from literature — core stages from interview data.
◇Under-explored areas are marked with dashed borders and ? icons. These represent gaps where our N=24 sample has limited or no coverage. They are flagged to guide future research priorities.
Evidence
Qualitative Scoring Matrix
Scores are directional estimates synthesized from N=24 interviews — not measured values. They represent the typical trajectory for each Well based on what participants reported across developmental stages.
Well
P3–P4 ≈
P5–P6
Sec 1
Sec 2
Sec 3
Sec 4
JC/Poly ≈
Scoring rubric (1–5 scale): 5 = Strong/healthy — habit consistently maintained, supported by structures 4 = Good — mostly maintained with minor lapses 3 = Mixed — inconsistent, depends on context and day 2 = Declining — more bad days than good, system supports weakening 1 = Poor — habit largely abandoned or severely disrupted
Evidence basis: Each score draws on multiple participant accounts describing behaviours at that developmental stage. Where fewer than 3 participants provide evidence for a stage, scores are marked with ≈ to indicate lower confidence.