Evolution, development, and the emergence of disgust

Area of Science:

• Evolutionary Psychology
• Developmental Psychology
• Comparative Psychology

Background:

• Evolutionary developmental psychology explains development through an evolutionary lens.
• Developmental evidence can inform and refine evolutionary theories.
• The evolved function of psychological traits can be evaluated using their developmental origins.

Purpose of the Study:

• To demonstrate how developmental evidence can inform evolutionary theory.
• To re-evaluate the proposed adaptive function of disgust using developmental data.
• To use the emotion of disgust as a case study for this approach.

Main Methods:

• Reviewing existing research on the developmental emergence of disgust.
• Comparing the developmental timeline of disgust with periods of vulnerability to pathogens.
• Analyzing the implications of developmental timing for evolutionary claims.

Main Results:

• Disgust and "disgust face" recognition do not reliably emerge until after age 5.
• This developmental timing contrasts with the period of highest vulnerability to ingested pathogens (ages 3-5).
• The late emergence challenges the claim that disgust evolved primarily for pathogen avoidance.

Conclusions:

• Developmental evidence is crucial for validating evolutionary hypotheses about psychological traits.
• The late ontogeny of disgust suggests its adaptive function may be more complex than simple pathogen avoidance.
• Further research is needed to understand the full adaptive role of disgust considering its developmental trajectory.