The slow and persistent decline of our uniqueness...

by Salman Hameed

Okay this might a bit too strong of a statement. But I was struck by two articles in last week's Nature. The first one was about the possible detection of two Earth-sized planets orbiting around a Sun-like star located about a 1000 light years away. The system is called Kepler 20, it consists of at least 5 planets - 3 comparable in size to Neptune and 2 Earth size. No - none of these planets are in the habitable zone. In fact, all of them have orbits smaller than Mercury. Liquid water probably doesn't exist on these planets - and most likely no life. But is there really any reason to believe that we won't find any earth-sized planet in the habitable zone of a sun-like star? If you are betting person, would you really bet against this possibility? In fact, guessing from the pace of things, I think we will have such candidate planets within the next 2-3 years, if not sooner. Wither the uniqueness of Earth.

And then we have competing animals threatening claims of the uniqueness of human intelligence. This should not completely a surprise considering the close genetic link between humans and some of its cousin apes. But here is a review of a collection of articles in a new book, Primate Minds: Built to Connect with Other Minds:

Ten years ago, human minds were thought to be unique in their ability to connect. But as The Primate Mind shows, there has been a revolution in our understanding. This collection of essays, the result of a 2009 conference organized by primatologist Frans de Waal and ethologist Pier Francesco Ferrari, presents an authoritative, surprising and enriching picture of our monkey and ape cousins. We now know that they have remarkably sophisticated social minds, and that their poor performance in social tasks set by humans was more a result of researchers asking the wrong questions than deficiencies in their experimental subjects.

And actually some of the wrong assumptions are quite fascinating:

            A. SHAH/NATURE PICTURE LIBRARYYoung chimpanzees watch and mimic an adult as she digs for termites, showing that the ability to learn by observing others is not unique to humans.

For example, a chapter by psychologists April Ruiz and Laurie Santos explores whether non-human primates can monitor where others are looking and use that information in their own decision-making — a test of whether the animal understands what another perceives. Primatologists first tested this by seeing whether monkeys followed an experimenter's gaze to find a box containing food. The animals performed unexpectedly poorly. But changing the task from cooperation to competition unleashed the primates' true potential: macaques readily stole food from humans who looked away, but refrained from doing so when watched. Placing the task in a setting more relevant to macaque social life, which is less cooperative than our own, emphasized the continuity between our social mind and that of our primate ancestors.

And this is a spectacular example of not only our misunderstanding, but also of our underestimation regarding ape intelligence:

The Primate Mind shows how this discrepancy between neural similarities and behavioural dissimilarities has been resolved. There is more than one way to copy others: one can either mimic every detail, or achieve the same goal by different means. Recent studies, reviewed in chapters by cognitive biologist Ludwig Huber and by primatologist Andrew Whiten and his colleagues, reveal that apes will rationally shift between these alternatives. 

If apes see a man pressing a button with his head because his hands are occupied holding a blanket, they will press the button with their hands. Apes thus demonstrate something smarter than simple imitation — the ability to infer why a person is doing something in a particular way. But if the man's hands are not occupied, giving the ape no clue as to why the person would push a button with his head, chimpanzees tend also to use their heads. It is one of many illustrations of how easy it is to misinterpret experimental results: the apes' ability to copy the details of an action only when it makes sense was misinterpreted as an inability to imitate fine details.

And here is the larger perspective:

One by one, claims to human uniqueness have fallen. Other essays by de Waal and anthropologists Brian Hare and Jingzhi Tan show that our primate cousins share empathy and the inclination to cooperate. Apes console other apes after conflict. Chimps overcome their fear of water to save a drowning chimp. Monkeys can favour actions that benefit other monkeys. Apes even recruit other apes to collaborate with them, and will negotiate a fair distribution of pay-offs. 

Clearly, we are different from other primates. I have never seen macaques display anything like a toddler's eagerness to imitate. The Primate Mind suggests that it may not be the capacity to imitate, but the motivation to do so that sets us apart from other animals. Like all good suggestions, this opens the door to more questions about the mechanisms and evolution of such motivation — and, ultimately, about how our own social minds evolved from the deeply interconnected minds of our primate cousins.

Read the full review here (you may need subscription to access it).

And far from being threatened by this decline of uniqueness, celebrate the interconnectedness. It is these connections that also illuminate the way things have come to be - from stars and planets to cauliflower and humans.