Chimpanzees and bonobos distinguish between risk and ambiguity.
Abstract
Although recent research has investigated animal decision-making under risk, little
is known about how animals choose under conditions of ambiguity when they lack information
about the available alternatives. Many models of choice behaviour assume that ambiguity
does not impact decision-makers, but studies of humans suggest that people tend to
be more averse to choosing ambiguous options than risky options with known probabilities.
To illuminate the evolutionary roots of human economic behaviour, we examined whether
our closest living relatives, chimpanzees (Pan troglodytes) and bonobos (Pan paniscus),
share this bias against ambiguity. Apes chose between a certain option that reliably
provided an intermediately preferred food type, and a variable option that could vary
in the probability that it provided a highly preferred food type. To examine the impact
of ambiguity on ape decision-making, we interspersed trials in which chimpanzees and
bonobos had no knowledge about the probabilities. Both species avoided the ambiguous
option compared with their choices for a risky option, indicating that ambiguity aversion
is shared by humans, bonobos and chimpanzees.
Type
Journal articlePermalink
https://hdl.handle.net/10161/6948Published Version (Please cite this version)
10.1098/rsbl.2010.0927Publication Info
Rosati, Alexandra G; & Hare, Brian (2011). Chimpanzees and bonobos distinguish between risk and ambiguity. Biol Lett, 7(1). pp. 15-18. 10.1098/rsbl.2010.0927. Retrieved from https://hdl.handle.net/10161/6948.This is constructed from limited available data and may be imprecise. To cite this
article, please review & use the official citation provided by the journal.
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Brian Hare
Professor of Evolutionary Anthropology

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