Data from: Bonobos and chimpanzees exhibit human-like framing effects

Humans exhibit framing effects when making choices, appraising decisions
involving losses differently from those involving gains. To directly test
for the evolutionary origin of this bias, we examined decision-making in
humans' closest living relatives: bonobos (Pan paniscus) and
chimpanzees (Pan troglodytes). We presented the largest sample of
non-humans to date (n = 40) with a simple task requiring minimal
experience. Apes made choices between a ‘framed’ option that provided
preferred food, and an alternative option that provided a constant amount
of intermediately preferred food. In the gain condition, apes experienced
a positive ‘gain’ event in which the framed option was initially presented
as one piece of food but sometimes was augmented to two. In the loss
condition, apes experienced a negative ‘loss' event in which they
initially saw two pieces but sometimes received only one. Both conditions
provided equal pay-offs, but apes chose the framed option more often in
the positive ‘gain’ frame. Moreover, male apes were more susceptible to
framing than were females. These results suggest that some human economic
biases are shared through common descent with other apes and highlight the
importance of comparative work in understanding the origins of individual
differences in human choice.