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Measuring the Subjective Value of Risky and Ambiguous Options using Experimental Economics and Functional MRI Methods
Published on: September 19, 2012
Chimpanzees and bonobos distinguish between risk and ambiguity
Alexandra G Rosati1, Brian Hare
1Department of Evolutionary Anthropology, Center for Cognitive Neuroscience, Duke University, Durham, NC 27708, USA. alexandra.rosati@duke.edu
Biology Letters
|November 26, 2010
Summary
Great apes, including chimpanzees and bonobos, exhibit ambiguity aversion, similar to humans. They prefer known risks over uncertain choices, suggesting shared evolutionary roots in economic behavior.
Area of Science:
- Behavioral Ecology
- Comparative Psychology
- Evolutionary Economics
Background:
- Limited understanding of animal decision-making under ambiguity, where information about alternatives is lacking.
- Human studies indicate a bias against ambiguous options compared to risky ones with known probabilities.
- Investigating ambiguity aversion in apes can illuminate evolutionary origins of human economic behavior.
Purpose of the Study:
- To determine if chimpanzees and bonobos exhibit ambiguity aversion.
- To compare ape decision-making under ambiguity with human economic behavior.
- To explore the evolutionary basis of ambiguity aversion.
Main Methods:
- Apes (chimpanzees and bonobos) were presented with choices between a certain food option and a variable option.
- The variable option's probability of yielding a preferred food varied, including trials with unknown probabilities (ambiguity).
- Choice patterns between certain, risky, and ambiguous options were analyzed.
Main Results:
- Both chimpanzees and bonobos demonstrated a preference against the ambiguous option.
- Apes avoided ambiguous choices more than risky choices with known probabilities.
- This suggests a shared aversion to ambiguity across humans and great apes.
Conclusions:
- Ambiguity aversion is not unique to humans and is present in our closest living relatives.
- Great apes share a bias against uncertainty, indicating deep evolutionary roots for this economic behavior.
- Findings contribute to understanding the evolutionary psychology of decision-making under uncertainty.
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