Without having tasted a specific new juice mix before, an orangutan in a Swedish zoo has enough sense to know whether it will taste nice or not based on how he recombined relevant memories from the past. Only humans were previously thought to have this ability of affective forecasting, in which prior experiences are used to conjure up mental pictures about totally new situations, says Gabriela-Alina Sauciuc of Lund University in Sweden, in Springer’s journal Animal Cognition.
In general, making decisions is much easier when one is guided by prior experience, but this is not always available in new situations. In such cases, affective forecasting becomes important. It enables people to predict whether a situation will be pleasurable or not, by mentally recombining elements of prior experiences into possible scenarios, and by allowing people to pre-experience what these might feel like. Affective forecasting saves people the costs and risks of having to engage in actual behaviour to find out how new situations might turn out.
This ability is believed to have evolved only in humans. For example, given prior experience with the ingredients, but in the absence of direct experience with the mixture, only humans are thought to be able to predict that lemonade tastes better with sugar than without it. In contrast, all other animals are thought to be stuck in their previous experiences. At best, they should be able to predict that the juice they tasted before will taste the same again. But they would be unable to realize that a novel mixture of known juices will have new gustatory qualities, which depend on those of the ingredients. Faced with such new situations, animals are expected to be clueless and act by trial-and-error.
To examine whether affective forecasting is indeed limited to humans, Sauciuc’s team developed a non-verbal test to …