Every so often there is a scientific article that should be read and shared for the title alone. I mean, how can you not revel in the image of your head consisting of layer after tear-producing layer enshrouding a lizard?

The one in question, a paper by scientists Joseph Cesario, David J. Johnson, and Heather L. Eisthen at Michigan State University, should be read for a more important insight, though. Not only do many of us, influenced by thinkers as long ago as the Greek philosophers, or as influential as Freud in our own times, conceive of our brain in ways that are wrong, but the majority of psychology textbooks, never mind common literature, perpetuate the false beliefs.

Put simply: we cling to the notion that there is an old reptilian part of the brain, that controls basic functions. Layered onto it is the limbic system that controls our emotional responses. On top of it is another layer, the cerebral cortex, which controls language, reasoning and rational actions. The tug of war between emotional reactions (hot) and deliberate reason (cold) is assigned to these regions and reserved for the evolutionary most complex species.

This notion includes some basic assumptions: that there are older anatomical structures (the animalistic drive center that only allows reflexive responses) and that there are newer structures that are reserved for more complex organism like humans, allowing for rational decision making, overriding the emotional response. They are seen as layered on top of each other, like geological strata that you can identify when you dig ever deeper onto the earth. And the notion assumes that we have evolved linearly from simple animals to highly complex ones, our own species included at the very top.

We’ll have to let go of this view. For one, neural and anatomical complexity evolved repeatedly within many independent lineages. Simply put, there is increasing complexity to be found in mammals and non-mammal species, octopus, sharks, birds for example show ever evolving incredible brain complexity and corresponding behavior.

The notion of layers of new structures added to existing structures across evolutionary time as species became more “complex” is also incorrect. All mammals, not just humans, have a pre-frontal cortex the part that controls reasoning, it is not uniquely human.

Most importantly, evolution does not proceed by laying down geological strata, one over the other, instead evolution changes existing parts, transforming them. That does not mean that everything earlier is completely wiped out (the “head vs. heart” tug of war is something we do still experience) but the belief that emotion and reason are located in evolutionary independent, untouched structures is scientifically untenable.

The paper goes on to discuss why it matters to change our mistaken views. I’ll leave it to you to read up on it if that is of interest. I will cheer us up in the short run with something related that I read yesterday referring to science, by Jan Mieszkowski, a Reed College professor in the German department:

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Lizards come in all sizes – one of the biggest is the green iguana. Iguanas are a favorite American pet, and all too often released into the wild after people get bored – there they wreck havoc. Florida, where today’s photographs were taken some time back, suffers substantial damage from these creatures who have not many natural predators, proliferate and threaten eco system and structures, river banks and golf courses alike. The video below is pretty graphic in what iguana hunters do, catching the lizards for kill, or to be sold to restaurants (their meat is a favorite for caribbean cuisine, “tree chicken,”) or to be sold for pets. It is an interesting sociological snapshot, though, which is why I decided to include it.

And here is the biggest lizzard of them all in a wonderful 1924 Fritz Lang rendition….of a Wagnerian Tarzan slaying the dragon.

Music is self explanatory….