We cannot define or explain consciousness.
We believe, with fairly good reason, that we are conscious. Rene Descartes famously said “I think, therefore I am,” thus claiming self-awareness is the seat of identity.
And where is the seat of self-awareness? In the brain. Common sense and medical science make it clear, that for homo sapiens, the brain is the home of consciousness. (Again, we don’t exactly know what we mean when we say “consciousness,” but whatever it is, we’re pretty sure it’s in the brain.)
And so, with typical human arrogance, we assume that all living things must think with their brains. Whales and dolphins famously have large brains, so we have looked for, and found, what we call intelligent, conscious behavior in whales and dolphins. Clearly, elephants have large brains. Close observation of elephants shows complex social and mental behavior.
Elephants use their trunks to manipulate tools, just as humans do. Baboons, chimpanzees and other primates with large brains use tools as well – and since humans use tools quite well, humans equate tool-making and tool use with intelligence.
In fact, there are many who believe that tool-making is what separated homo sapiens from the many competitors it has outlasted and driven extinct. The big-brained humans figured out to use a variety of tools, and simply out-competed the rest of the flora and fauna on the planet, and now sit comfortably at the crown of creation.
So the human brain has around 1,350 grams of material, packed in a very small area. A bird like a cockatoo has a brain the the size of a walnut, about 3 grams. That means a cockatoo has less than a third of one percent of the brain capacity of a human being.
And yet a cockatoo uses tools. Cockatoos, small birds that max out at about two pounds, use sticks to break termite mounds so they can feast on the insects inside. (Have you ever seen a dog use a tool? A dog’s brain is much larger.)
Fine, so cockatoos use sticks. Impressive, certainly, for having a brain so tiny it would fit in an infant’s fist. But actually cockatoos use two different kinds of sticks for different jobs. The stick they use to break open a termite mound is different than the one they use to probe inside the tunnels and drive the termites out. And clearly they know which one is which.
OK, so they’re smart birds. But how about this? They bring their tools with them when they go foraging. They have a tool kit. Of course, if they know they only need one tool, they just bring that tool. If they’re not sure, they bring two.
And their brain is the size of a walnut.
Could it be, just maybe, that brain size isn’t as important as humans like to believe it is? Could it be we want to believe big brains are important because we happen to have big brains? If we had the biggest eyes on the planet, would we would believe that the eyesight was the most important attribute of an advanced species?
And given what cockatoos do with their tiny brains, maybe “thinking” (whatever that might be, because despite our big brains, we have no idea what it is) can be done without a bunch of grey stuff stuck inside a bony carapace. Maybe thinking takes more, or less, than that. Maybe self-awareness is no more dependent on brain size than the ability to use tools.
So maybe we should look very carefully at the world around us. Studies on plants, for example, record electrical signals when they are attacked by predators or humans about to harvest them. Are those signals thoughts? The cockatoo can think pretty well with a tiny brain – who’s to say that there aren’t other ways of “thinking,” other kinds of self-awareness.
At this point, even those who have been willing to suspend a little disbelief have probably given up. OK, birds are smart, but plants? Really?
A question, then: What does the ability to move have to do with the ability to be self-aware, to think? What does movement add?
Another question: A redwood tree weighs about 1.4 million pounds and can live for thousands of years. Is it possible that a very few of those 1.4 million pounds – say the same amount as about a thousand human brains – are self-aware in some manner?
Of course not, is the reflexive answer. But really, why so sure? We can’t explain what it means for humans to be conscious, so why are we so convinced that a redwood tree, or even a rose bush, can’t possibly be self-aware, or care if a human cuts it down or clips a blossom?
We could ask the best and the brightest of our own species, and they could not give us a definitive answer. Of course, if they could speak our language (or we could speak theirs), we could try asking a cockatoo.