Cognitive Daily

Cross another ability off the “humans only” list

Posted by Dave Munger on February 22, 2007
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As was noted with irony a few days ago, many psychologists feel obligated to describe the abilities that make humans unique. Perhaps this trait itself is part of human nature: we’re constantly seeking to justify our actions — many of which harm other organisms.

When we learn that an animal can, for example, recognize itself in a mirror, we begin to wonder if we’re really so different from the other animals; whether our dominance over the world is really merited. The latest study covering such ground involves the scrub jay, a remarkable bird which hides its food in thousands of caches, remembering where they are and tracking whether each cache has been discovered by a rival bird.

Researchers have now identified another humanlike behavior in the scrub jay: planning for the future. Neurophilosopher has the details:

During their training, the birds were confined to one of the side compartments in the mornings, after not eating during the night. In the ‘breakfast’ room, they were given powdered pine nuts, which they could not store, whereas in the ‘no breakfast’ room they were given no food. Over a period of 8 days, the birds’ confinement alternated between these two rooms. After training, they were unexpectedly presented, in the evening, with whole instead of powdered pine nuts in the central room. It was found that the birds collected the nuts and stored them in sand-filled trays in the side compartments. The jays cached the nuts in the ‘no breakfast’ room far more frequently than in the ‘breakfast’ room, in anticipation of being confined there without food the next morning.

In a second study, a different food was provided in each room, with no “no food” option. The jays cached each type of food in the other room, apparently anticipating the need for a variety of foods.

The implication is that these birds aren’t simply caching food due to instinct, but are actually imagining a foodless future. Humans, it appears, aren’t the only creatures with such abilities; some (but not all) birds have them too!

Some people don’t eat meat at all because they are concerned about the moral implications of killing another sentient being. Some people draw the line at the mammal/non-mammal boundary. Most of us won’t eat primates or dolphins. Of course, all such lines are arbitrary, but research such as this study does demonstrate that there is amazing variety of mental ability even in animals that are only distantly related to humans: just one more thing to think about next time you’re trying to decide between the smoked salmon and braised duck.

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Comments

  1. #1 Rob Knop
    February 22, 2007

    The implication is that these birds aren’t simply caching food due to instinct, but are actually imagining a foodless future.

    Of course, there’s a semantic question buried in there: perhaps it is due to instinct. But, then, perhaps that thing that we interpret as our own imagination is also just instinct. In both cases, a pretty complicated and sophisticated instinct, but….

    The need to say that humans are qualitatively different from other animals is one of the things that supports anti-evolution. Even if you’re completely convinced by the evidence for evolution and have no problem with it, believing that humans are a “phase change” away from all other animals is a powerful reason to want to pay attention to something like intelligent design creationism.

    Of course, a reductionist view could lead us to believe that all morality is arbitrary, and then to think that deciding between the salmon and imitating the Donner Party just for fun doesn’t really have any moral implications…. Alas, one must think, instead of ascribing to simplistic yes/no principles, and thinking is hard.

    -Rob

  2. #2 Dave Munger
    February 22, 2007

    The need to say that humans are qualitatively different from other animals is one of the things that supports anti-evolution.

    Sure, but you could be a fervent supporter of the theory of evolution and believe that humans are still significantly different from all other organisms. Believing humans are different doesn’t necessarily make you anti-evolution.

    And honestly, there’s still an awful lot of difference between humans and other animals. The difficulty is describing exactly how we’re different.

  3. #3 Dave Munger
    February 22, 2007

    Oh, and welcome to ScienceBlogs, Rob!

    Check out Rob’s new digs here.

  4. #4 The Ridger
    February 22, 2007

    When birds start planting trees to give them nuts in five years, then they’re “planning for the future”. These may just be going on the pattern of how hard food is to find in the mornings … Don’t lots of animals hide food to eat later? Is that really “planning for the future”?

  5. #5 Dave Munger
    February 22, 2007

    Don’t lots of animals hide food to eat later? Is that really “planning for the future”?

    I suppose, but it’s also possible that these animals evolved this behavior without conscious “planning.” If an animal has a tendency to bury half its food, and separately has the ability to locate that food later, that might be adaptive, but can we say it’s “planning”?

    By controlling the experiment in the way they did, the researchers eliminated many possible explanations of the behavior other than “planning.”

    Again, I’m not saying these birds are “human,” but “planning” is one of those things people have invoked to show that humans are different from animals.

    When it was found that some animals do use tools, therefore tool use was not uniquely human, a typical response was “that may be true, but only humans plan to use tools in the future. Animals are opportunistic tool users, and that’s why humans are different.”

  6. #6 Simon Greenhill
    February 22, 2007

    @The Ridger -

    This is not simple “planning for the future”, and is a follow-up to Nicky Clayton’s previous work on caching in scrub jays. Their previous work has shown content dependant caching.

    So – scrub jays given two types of food; worms and nuts. They prefer worms over nuts, but worms tend to go off after a few days. Clayton etc found that the jays will cache both things but will only get the worms for a few days before switching to the nuts. They argue that this demonstrates forward planning, and do quite a number of elegant experiments to tie this down quite nicely (IMO).

    If you’re interested in this debate, look out for papers by Clayton and Harvey vs. Thomas Suddendorf (they had an exchange in Trends in Cog. Sciences a few years ago from memory), on “Mental Time Travel”.

    –Simon