Though us humans often like to congratulate ourselves on being the smartest of all primates, a spate of recent studies has begun to suggest that some of our closest evolutionary cousins are not actually as far behind us as we thought. The latest of these reveals that orangutans are able to engage in “active forecasting”, meaning the prediction of sensory outcomes of scenarios that have never been experienced before. Until now, this ability had been considered unique to humans.
A prime example of active forecasting is what researchers call “mental taste blending”, meaning the ability to guess how certain foods will taste based on their ingredients, despite having never previously tried that particular recipe. Abilities like this are important as they allow us to figure out the pros and cons of certain actions without having to actually carry them out in order to find out what their consequences will be.
To figure out if this is indeed an exclusively human trait, researchers designed a cocktail-tasting experiment using a male Sumatran orangutan named Naong, and 10 human participants. First, Naong spent time familiarizing himself with the taste of three different juices – cherry, rhubarb, and lemon – as well as apple cider vinegar.
Based on which of these he drank most eagerly, the research concluded that cherry juice was clearly Naong’s favorite, followed by rhubarb juice. Lemon juice and vinegar, however, appeared to offend his palate, and he did not hide his reluctance to drink them.
Once these preferences had been established, the team created a number of cocktails using various amounts of these four ingredients, while Naong watched them mix these concoctions. He was then presented with pairs of cocktails, of which he had to choose one to drink.
Describing their findings in the journal Animal Cognition, the study authors explain how Naong’s choices were so consistent with his preferences for individual flavors that he could not have been selecting cocktails using mere trial-and-error. Significantly, his performance was found to be within the range of that of the 10 human participants who also took part in the challenge.
For instance, Naong was able to discern that drinks containing higher concentrations of cherry or rhubarb juice, and lower concentrations of lemon juice or vinegar, would taste better, even before he had tried these mixtures.
According to the researchers, this finding “challenges the hypothesis that active forecasting is an ability restricted to humans and suggests ancient evolutionarily roots for this crucial human ability.”