The number of traits chalked up as “distinctly human” seem to dwindle each year. And now, we can’t even say that we’re uniquely aware of the limits of our knowledge: It seems that some monkeys understand uncertainty too.
A team of researchers taught macaques how to maneuver a joystick to indicate whether the pixel density on a screen was sparse or dense. Given a pixel scenario, the monkeys would maneuver a joystick to a letter S (for sparse) or D (for dense). They were given a treat when they selected the correct answer, but when they were wrong, the game paused for a couple seconds. A third possible answer, though, allowed the monkeys to select a question mark, and thereby forgo the pause (and potentially get more treats).
And as John David Smith, a researcher at SUNY Buffalo, and Michael Beran, a researcher at Georgia State University, announced at the AAAS meeting this weekend, the macaques selected the question mark just as humans do when they encounter a mind-stumping question. As Smith told the BBC, “Monkeys apparently appreciate when they are likely to make an error…. They seem to know when they don’t know.”
We’ve all seen this scene being played out in the local park: When a guy walks a cute dog, people don’t hesitate to approach him to strike up a conversation about schnauzer breeds. Or there’s the guy-with-a-baby scenario, in which the baby-hauling dad is perceived as friendly and non-threatening (not to mention irresistible to some women).
Now, new research from France suggests that male Barbary macaques may be onto the same “baby effect” strategy. The study found that male macaques with an infant were more likely to make male monkey buddies, as the presence of a tiny, defenseless baby immediately breaks down barriers.
The study, which is due to be published in the journal Animal Behavior, is also the first to demonstrate that infants can serve as social tools for some primates, writes Discovery News.