Related Experiment Videos
Reaching reveals that best-versus-rest processing contributes to biased decision making.
Nathan J Wispinski1, Grace Truong2, Todd C Handy2
1Department of Psychology, University of Alberta, Canada.
Acta Psychologica
|April 3, 2017
Summary
Human decision-making shows bias, particularly with risky choices. This study finds that the best option is favored in action, not just perceived probability, influencing choices even in riskless scenarios.
Area of Science:
- Cognitive Psychology
- Neuroscience
- Behavioral Economics
Background:
- Human decision-making often exhibits systematic biases, especially in probabilistic or risky choice scenarios.
- The extreme-outcome rule suggests people overvalue both the best and worst outcomes when learning probabilities through experience.
- This bias is hypothesized to stem from a disproportionate subjective weighting of extreme values.
Purpose of the Study:
- To investigate if the extreme-outcome rule in decision-making is partly caused by overweighting extreme values.
- To test the extreme-outcome rule in a controlled, riskless decision-making task.
Main Methods:
- Participants performed a riskless choice task, selecting between options with consistent outcomes.
- Decision enactment (reaction times, reaching movements) and choice accuracy were analyzed.
- The study contrasted observed behavior with predictions based on probability overestimation.
Main Results:
- Overvaluation of extreme outcomes was observed even in the absence of probabilistic elements.
- Strong evidence supports the overvaluation of the best outcome in decision enactment (reaction times, movements).
- No evidence for overvaluation of extreme outcomes was found in choice accuracy.
Conclusions:
- The extreme-outcome rule may not solely result from overestimating choice probabilities.
- A 'best option boost' in processing, relative to other options, offers a simpler explanation for observed biases.
- Findings suggest biases in decision-making enactment, not just probability perception.