Tuesday, December 13, 2011


Look at me! I'm a highly advanced vertebrate and I'm using a machine built by other members of my species to produce words on a screen. Those words are going to be sent to yet other members of my species and perhaps they will read. Perhaps they will learn.

It would appear that I am behaving. Because of a combination of internal and external stimuli I am engaging the world and acting on it.

Now what about a plant? A plant can turn to meet the sunlight. Some plants, like a Venus flytrap, can even catch animals and "digest" them. Does a plant behave? Most people would probably say no, that a plant "reacts" to its environment. But in a strictly Skinnerian way of looking at things I'm not so different from the plant. If you observe us we move. We attempt to get closer to food, water, etc., the things that make us survive.

I've been thinking about this stark comparison for two reasons: First, I've been talking about behavior a lot with school children around grade 4 or so and when you ask them what behavior is they usually tell you something like "well, it's when you've got good behavior or you've got bad behavior and that's when your mom and dad tell you to behave." From my conversations it seems like one of those words that children use but don't really understand.

But I'm not really sure us adults understand it any better. When I define the word for my students I usually say "it's what the animal does" (this is in the context of studying animal behavior). But if you tried to apply that definition to say, a car, you'd sound a little weird. "The car is behaving. It's behavior is...what the car does." Clearly cars do stuff but we know there's nothing internal that's directing their behavior. So is that internal response to external stimuli what makes the "does" behavior and not just "does?"

The other reason I've been thinking about behavior and what it means exactly is because I finally caught up with some research that came out a while back that led some to claim that cnidarian jellyfish (just jellyfish for those who don't care to think too hard about taxonomy today) have brains. Previous thinking was that all they had was a "neural net," too diffuse and sparse to control any kind of directed behavior. The difference between your brain and any old neuron is that your brain's neurons are all super close together and there's a lot of them so all the neurons can be assigned different jobs and they can all talk really quickly together. Unlike the neurons that detect pain or move my muscles, for example, they are the ones really producing the behaviors rather than just carrying them out. Most invertebrates have what we call "ganglia" which are kind of like proto-brains so to claim a jellyfish had a brain...seemed ridiculous.

And it was. You may remember this story if you follow The Science Journalism. It was covered in the New York times. Here's a link to the story. I think this is just horrible science journalism and here's why: I went to the abstract of the actual paper. It does no such thing as to claim jellyfish have brains. It claims they have some centralized "ganglia-like" (so think proto-ganglia or proto-proto-brain) nerve clusters. The author does not use the word "brain."

It's a second scientist quoted in the paper, one Doctor "David J. Albert, a jellyfish expert at the Roscoe Bay Marine Biological Laboratory in Vancouver, British Columbia" who makes the following claim: "That's what a brain does. It controls behavior." The journalist fills in the bit about if it behaves, which it turns out jellyfish do sometimes, then it must have a brain. But reading the sentence over and over it really seems like that's what Dr. Albert meant. That's what a brain does, it controls behavior. Therefore if you have behavior you must have a brain. (Those are my words, notice no quotations).

So let's not argue over terminology. The jellyfish have some kind of neuronal organization that produces directed behavior. But a plant also has some kind of physiological organization, albeit not neuronal, that allows it to react to its environment. How are these two systems different? NEURONS!

So this has been a bit long but here's my summation: I believe that we do not know what the word behave means. I think that if scientists are willing to apply it to jellyfish and not plants then we have a "neuron-centric" perspective. I believe that when we use the word behavior we must impose some black and white distinction between entities that do have "directed behavior" from those that do not and I believe this is a false, blurry utterly grey distinction.

I don't think there's really a moral or educational lesson here. Just something to think about the next time you use the word "behavior."

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