About Rationally Speaking

Rationally Speaking is a blog maintained by Prof. Massimo Pigliucci, a philosopher at the City University of New York. The blog reflects the Enlightenment figure Marquis de Condorcet's idea of what a public intellectual (yes, we know, that's such a bad word) ought to be: someone who devotes himself to "the tracking down of prejudices in the hiding places where priests, the schools, the government, and all long-established institutions had gathered and protected them." You're welcome. Please notice that the contents of this blog can be reprinted under the standard Creative Commons license.

Friday, July 06, 2012

RS encore: One more non-difference between humans and animals

by Massimo Pigliucci

Humanity has a long history of narcissism, characterized by an endless quest for what makes us “unique,” different from “mere” animals, and – by implication – more likely to be the gods' favorite creatures. Aristotle thought that reasoning was the key to humanity, which led him to suggest that the most perfect life is, of course, that of the contemplative philosopher (hey, at least he didn't go as far as his mentor, Plato, who actually advocated that philosophers should be kings!).

Of course, the perennial hostility generated by the scientific view of humans as animals sharing a common descent with other primates also falls along the same lines: some of us just won't admit that we are animals. Sophisticated, yes, capable of appreciating fine art and killing millions at the push of a button, yes, but animals nonetheless.

A recent study published in Science (17 February 2006) by Aaron Blaisdell, Kosuke Sawa, Kenneth Leising and Michael Waldmann chips away one more brick in the defense wall allegedly separating us from the rest of nature. They studied reasoning abilities in rats, and came to rather startling conclusions. First of all, it has been well known that rats (and other rodents) can “reason” in the sense that they can make associations between phenomena that guides their behavior. For example, they can note a correlation between event A (say, the appearance of a light) and event C (food will be dispensed), and rapidly come to expect C whenever they see A (such expectation can be measured, for example, by the fact that after seeing the light the rats immediately start poking their nose in the directions where the food is supposed to come from).

This may not sound very impressive, but it is in fact the same sort of inductive reasoning that most of us, scientists included, use every day: one observes a few instances of a phenomenon and generalizes to a broader set of events. Of course, inductive reasoning of this sort is rather unreliable, as summarized in the mantra that “causation is not correlation” (though the quip often associated with it is that “the two are nonetheless highly correlated”).

Humans, it was thought until Blaisdell and coworkers' paper was published, are still the only animals capable of causal inferences, i.e. of a more sophisticated mixture of inductive and deductive approaches that allows us to go beyond simple correlations and actually construct a mental model of the causal connections behind events. For example, we realize that weather conditions, air pressure and barometer readings are all correlated, but we also understand that manipulating a barometer will do precisely nothing to change the weather.

Well, apparently, so do rats. Blaisdell's group carried out a series of elegant experiments in which rats were trained under two situations: first they were exposed to a flash of light (event A), followed by both a noise (event B) and eventually food (event C). This generated the classical type of correlational expectation, so that rats would increase their nose poking in response to either the light or the noise, “thinking” that both events were predictive of the good stuff soon coming their way.

The second situation was more interesting: rats were allowed to press a lever that would cause the noise (event B). Since the food (event C) wasn't coming after they pressed the lever – but was still being delivered after the light flash (event A) -- the rats had the opportunity of “deducing” a more sophisticated causal model, in which A and B were in fact decoupled, and only A would count as a reliable predictor of C. And they did! Once they got used to generating the noise by pressing the lever, they stopped expecting the food in response to it. It was like realizing that changing the barometer's setting isn't going to get you a sunny day after all.

Now, nobody is suggesting that all of this happens consciously, of course, and Blaisdell et al. do not expect rats to start publishing papers on the philosophical nature of causality. But by the same token, most of us don't reach similar conclusions consciously either. We are capable of articulating a reason for why we behave in a certain way, but much of our thinking is in fact unconscious. We ain't that different from rats, as it turns out, yet another little blow to our innate narcissism. Hey, perhaps it is the latter that is a truly unique human character? I wonder what sort of experiment we could carry out to test that hypothesis...


  1. No takers on this one yet. I have a theory, but let me say first it is not narcissistic, but self-respecting. The main difference between humans and other animals, apart from greater processing power from more intricate functions generally (which I will leave for now), is anticipation. Animals may have sensory processing priortized across evolution for sensory awareness of a niche and literal embededness, and motor processing in premotor might not provide adequate anticipation of future outputs...until humans.

    My proposal is that other animals sense amazingly, both of specifics of nature around them and their own enjoyments of those specifics, and sensorily adapt to the strokes of nature's baton to continue those enjoyments in limted niche behavior. Humans might have evolved premotor to use anticipation for the control of outputs for intricate ordered movement to construct in the world, and to know and control our constructions.

    We do not merely enjoy the moment as a sensory satisfaction, but also as a motor anticipation for control. We stay ahead of the game, and need extra processing for that feature. You can read about this further in the middle chapters of my theory at http://home.iprimus.com.au/marcus60/1.pdf

  2. All I have to do to know my dog anticipates, and will structure events in order to get what he is anticipating, is to watch him through the day. When he wants to go for a hike in the woods, he will walk over to his leash and harness and nose at it with a huge goofy smile on his face. When he wants us to play with him, he goes to his toy basket and pulls out whatever toy he wants, and places it in our laps... again, with a completely different facial expression than he normally has on.

    Now, maybe you mean something entirely different, but I'm fairly sure my dog knows how to manipulate me and my fiance in order to get things that he enjoys.

    1. Manipulation as a controlled intention by other animals would of course exist to some extent. I mean that humans are more complete in that than other animals. A dog might be driven sensorily by enjoyment, but it would undertake conditioned actions to satisfy it, if it is repeatedly successful at getting your response.

      That enjoyment somehow also extends to enduring controlled actions that cause it pain under instruction from a master (although in many cases that makes sense to avoid greater pains or sufferings of different kinds from the mater's training). So, whether the driver is sensory satisfaction or motor control is an open issue, but I would tend to say it is equal in humans and swayed to sensory in other animals, as a woking hypothesis for further analysis.

  3. Narcissism = self love, starts with self reflection which through the momentum of habit becomes excessive = Narcissism.

    So there - apart from capacity, size, shape, function or the burden of education - you have the difference, 'excessive' self reflection.

    A form of madness. Everybody knows the pain of excessive thinking, at some time, or emotional possession - the anger that destroys against better judgment. It can't be called sane, though it is normal.

    That's what separates us from the animal, insanity. Simple.

  4. I really dont understand this passion among scientists for claiming that we are 'the same' as animals (rats in this case. Normally Massimo seems too sophisticated to follow such a trend, but he's produced a typical example here.

    This idea that there is one or a few small poorly defined characteristics that makes us unique is a total straw man - no one serious thinks that. What makes us unique is how we combine characteristics found in many other species to become capable of far more than any of them. A comments box is hardly the place to go into all the different ways how - in any case the evidence is right in front of our eyes. How many other species have scientists, or could have created something like the internet? We look pretty unique to me


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