The Right Brain at the Right Place at the Right Time

Our prehistoric ancestors are the ones who did the heavy mental lifting for which we owe our expanded frontal cortexes. So who has the right brain for today?


What's the Big Idea?

This is a tale of two brains. One is Einstein's brain. The other is the Paleolithic brain. In the past few weeks we have learned significant insights about both, and how each one was uniquely qualified for the mental challenges of its time. 

Let's start with Einstein. While his brain was the same size of a normal human, as some newly published photographs of his brain reveal, those images also show unusual convolutions and folds. The lead researcher of the Einstein brain study, anthropologist Dean Falk, thinks this complex brain architecture may be the result of Einstein using "his motor cortex in extraordinary ways." In other words, by doing the 'muscular thinking' of complex physics, Einstein "programmed his own brain," causing it to expand.

It helped that Einstein had good material to work with. The field of physics was ripe for new insights, Falk observes, meaning that Einstein happened to have "the right brain in the right place at the right time." Well said. 

Now let's contrast the story of Einstein's brain with a seemingly depressing assessment of our contemporary brains by Stanford biologist Gerald Crabtree. In his recent article Our Fragile Intellect, Crabtree argues that human intellectual fitness has been on a slow but steady decay for 3,000 years, due to our relatively easy lifestyle that has freed us from a state of survival by thinking. In other words, civilization has allowed us to be quite dumb and survive just fine. As a result, civilization has left us vulnerable to thousands of naturally occurring mutations.

Crabtree's analysis points to "about 5000 new mutations in the past 3000 years (~120 generations)," a fraction of which "will produce a change within a gene or its regulatory regions that will be harmful." So how do contemporary humans stack up against the people of antiquity. Crabtree argues:


What's the Significance?

So what should we make of this? For one thing, we ought to give our ancestors the respect they deserve. After all, our prehistoric ancestors are the ones who did the heavy mental lifting for which we owe our expanded frontal cortexes. 

Oxford geneticist Bryan Sykes ecchoed this sentiment in a recent interview with Big Think:

I’m very proud of all of my ancestors that have got their DNA through to me, and I think everybody should be, particularly in America.  Because all of you have ancestors that took a lot of trouble to get here, whether it was across the frozen wastes of Siberia or more recently on ships from Europe or, unfortunately, ships from Africa against your ancestors’ will.  But everybody’s undergone an important and difficult journey to get here.

If we truly want to pay a debt of gratitude to our ancestors we need to not only reassess them, but also ourselves. The 21st century brain has its own set of challenges to figure out. While our ancestors needed to outsmart the competition that was stronger and faster, we need to catch up to our own runaway growth and devise plans for a sustainable future.  

So to brings things back around to Einstein, Crabtree asks, "How did we get from accurately throwing a spear to the theory of relativity?" Crabtree points to a paradox in the field of Artificial Intelligence:

AI promised household robots that would wash dishes, mow the lawn, and bring us freshly cooked croissants and coffee in the morning. Needless to say we do not have these robots now and none of the readers of this piece will probably ever see them, despite the immense financial impetus to build them. This is because common tasks are actually conceptually complex. However, AI is very good at things we superficially consider intellectual, such as playing chess, winning Jeopardy, flying a jet plane, or driving a car.

To understand this paradox, consider the game Foldit, in which players predict protein structures. Humans beat supercomputers at this game in much the same way that we can wash the dishes and put them away better than a robot. We win because Foldit uses spatial reasoning skills that were perfected and selected for in our hunter-gatherer ancestors.

Many kinds of modern refined intellectual activity (by which our children are judged) may not necessarily require more innovation, synthesis, or creativity than more ancient forms: inventing the bow-and-arrow, which seems to have occurred only once about 40 000 years ago, was probably as complex an intellectual task as inventing language. Selection could easily have operated on common (but computationally complex) tasks such as building a shelter, and then 
computationally simple tasks, such as playing chess, became possible as a collateral effect. Loss of any one of 2000-5000 genes prevents us from effectively doing everyday tasks, and selection for the ability to perform them would optimize the function of the entire group of genes. 

So who has the right brain for today? There isn't one. The good news is that we have intellectual diversity. We don't all need to be exceptionally skilled hunter-gatherers, and that is a good thing. We get Mozart. We get Einstein. We get all of the creators of an intellectually robust society that, as Crabtree admits, accelerates knowledge accumulation:

One does not need to imagine a day when we could no longer comprehend the problem, or counteract the slow decay in the genes underlying our intellectual fitness, or have visions of the world population docilely watching reruns on televisions they can no longer build. It is exceedingly unlikely that a few hundred years will make any difference for the rate of change that might be occurring. Remarkably, it seems that although our genomes are fragile, our society is robust almost entirely by virtue of education, which allows strengths to be rapidly distributed to all members. The sciences have come so far in the past 100 years that we can safely predict that the accelerating rate of knowledge accumulation within our intellectually robust society will lead to the solution of this potentially very difficult problem by socially and 
morally acceptable means.

Image courtesy of Shutterstock
Follow Daniel Honan on Twitter @Daniel Honan

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