Opinion – Suzana Herculano-Houzel: Brainless behavior

I learned this weekend, listening to a book on animal behavior, that it seems that psychology still has a hard time agreeing on what behavior is. I love the irony, because psychology is exactly the field that studies… behavior. Of course, not having a good definition of the field of study is not exclusive to psychologists: neuroscience itself barely knows how to stagger an answer to “what is consciousness”, what the brain produces.

I believe that the problem in both cases is human arrogance, which thinks that behavior and conscience are the prerogatives of our species, and only very special cases are worthy of inclusion in our club. That’s where the studies begin that seek to discover what “only humans have” — and that fail, since the human brain is in many ways just another vertebrate brain, with just a cerebral cortex full of neurons.

Hence the expectation that “behavior” must be “what the human brain produces”. No useless circularity. Instead of definition, the book’s author (the name is irrelevant) proposes that behavior be defined by exclusion, with the “dead man test”: if a “dead man” can still do it, then it wasn’t behavior. The poor man died and lost what he didn’t even know how to define…

Because not knowing that the definition was a fight, and needing an operational definition to understand what brains add to behavior, I went there and adopted a very simple one. It goes like this: behavior is every observable action. Does the kid put his finger on his nose? It’s behavior. Does the robot dance? It’s behavior. Does the amoeba eat paramecium? Does the fan swing from side to side? Does the Moon orbit the Earth? All of this is behavior, which doesn’t need a brain, let alone a life—only energy in flux.

Interesting question, now yes, is what the brain, or nervous system, adds to behavior. The actions of brainless living beings —bacteria, fungi, plants— are stereotyped and quite predictable. Some change is always possible, as every cell is capable of losing sensitivity to what is always present. But without a brain, memory is very limited, and life is somewhat inflexible. The fan swings back and forth, rain or shine, as long as it’s plugged in and its circuits work.

But with a brain, behavior becomes flexible, able to find associations between events and create new actions rather than just responding stupidly to events. With a cerebral cortex, especially one full of neurons and, therefore, possibilities, like ours, behavior gains past and future, the ability to simulate other realities, to then act in favor of the desired ones and do what they can to avoid the unwanted ones. .

The new reality doesn’t have to be perfect; the brain sometimes knows how to give up what it wants to avoid what it doesn’t want at all. The important thing is that, with a brain, we can simulate the future — and act accordingly now. Or October 2nd…