From risk factors to protective capacity
Sudden Infant Death Syndrome has mainly been described through risk: characteristics of the infant, the environment and the developmental period that can combine in a lethal outcome.
The 2024 paper Death from Failed Protection? does not reject that knowledge. It asks what may be missing when risk is the only organizing idea. Most infants encounter ordinary physiological challenges during sleep without dying. What normally protects them, and how does that protection develop?
The authors propose an evolutionary-developmental model in which vulnerability can arise when current regulatory demands exceed an infant’s current protective abilities. Those abilities include arousal, autonomic regulation, caregiver proximity and other layers of protection that change across development.
Renz-Polster H, Blair PS, Ball HL, Jenni OG, De Bock F. “Death from Failed Protection? An Evolutionary-Developmental Theory of Sudden Infant Death Syndrome.” Human Nature 35, 153–196.
Read the full paper at PubMed Central →An evolutionary-developmental frame
The model brings together evolutionary theory, developmental biology and cultural mismatch. It considers why prone sleep and bed-sharing have complex relationships with SIDS rather than treating those relationships as simple, context-free causes.
This is a conceptual synthesis, not a clinical trial and not a replacement for established safe-sleep guidance. Its contribution is a broader framework for research: alongside asking which conditions increase risk, investigate the systems that ordinarily provide resilience.
Articles & explainers
These English-language pieces by Herbert Renz-Polster introduce the model at different levels of detail. They are explanatory articles, not additional peer-reviewed studies.
What protects infants from Sudden Infant Death Syndrome? follows the developmental transition from newborn reflexes to learned protective behavior and explains the questions behind the evolutionary-developmental model.
Read the explainer →Sudden Infant Death Syndrome — Don’t Forget the Guardian Angels! sets out the limits of the classic triple-risk model and asks why resilience also belongs in the scientific picture.
Read the background article →SIDS — European research group presents explanatory model offers a concise orientation to the paper’s central argument, proposed mechanism and possible research implications.
Read the publication summary →Safety context
This research page explains a scientific model. It does not provide individualized infant-sleep advice. Parents and caregivers should follow current safe-sleep recommendations from their national pediatric and public-health authorities and discuss individual circumstances with a qualified clinician.