Allowed response time and estimated average body size influence visual body size estimates

Area of Science:

• Cognitive Psychology
• Body Image Research
• Perceptual Science

Background:

• Body size estimation often exhibits a contraction bias, where individuals with lower BMI overestimate and those with higher BMI underestimate their body size.
• The influence of response time and perceived average body size on this bias requires further investigation.

Purpose of the Study:

• To replicate the contraction bias in body size estimation.
• To examine the relationship between allowed response time, estimates of average body size, and body size misperception.
• To investigate the context-specific nature of the contraction bias.

Main Methods:

• A replication study involving 277 neurotypical female Dutch participants.
• Body size estimation using a modified forced-choice task with varied response times and a method-of-adjustment task.
• Participants also estimated average and ideal body sizes for their demographic group.

Main Results:

• No direct evidence of contraction bias was found in the primary tasks.
• Estimates of average body size significantly predicted misestimation of own body size, aligning with contraction bias predictions.
• Increased allowed response time led to greater body size overestimation in participants with higher BMIs.

Conclusions:

• The contraction bias appears to be context-sensitive, influenced by factors beyond simple BMI categorization.
• Allowed response time significantly impacts visual body size misestimation, particularly for individuals with higher BMIs.
• Perceived population norms for body size play a crucial role in individual body size perception.