Sunday, February 12, 2012

Charles Darwin and Evolutionary Psychiatry

In honor of Darwin's 2003rd birthday, from mcmanweb ...

Here's an interesting fact: Peacock tails drove Darwin crazy. The sight of one "makes me sick," he wrote. These feathered accessories played havoc with his work-in-progress theory of natural selection. Surely, any bird stupid enough to flaunt their colors in the wild wouldn't live long enough to mate.

Darwin's solution seems obvious enough today, but back in the nineteenth century it was a scientific breakthrough, a work of genius. The showy tails, he figured out, were chick magnets. The flashier, the better. The well-endowed cock, so to speak, won the right to make a deposit. The bird's genes would live on, even if its owners' days were numbered.

Evolutionary biologists refer to this as a trade-off. A high fever, for instance, may aid in the destruction of deadly pathogens, and without the inconvenience of coughing we would all likely die from pneumonia. Take away our ability to experience pain and we would never know our appendix has burst. The sickle cell gene, in turn, is protection against malaria.

A Darwinian Explanation for Mental Illness

Fine. But how does Darwin apply to mental illness? According to evolutionary biologist Randolph Nesse MD of the University of Michigan:

Psychiatrists still act as if all anxiety, sadness, and jealousy is abnormal and they don't yet look for the selective advantages of genes that predispose to schizophrenia and bipolar disorder.

I heard Dr Nesse at the 2005 American Psychiatric Association annual meeting talk about the selective advantage in anxiety. Obviously, sufficiently anxious cave men and women were able to steer clear of saber toothed tigers long enough to find an opportunity to pass on their genes to the next generation.

Dr Nesse asks us to imagine a distant ancestor of ours at an ancient watering hole. The poor guy hears a sound behind him. A lion? A monkey? Even if it’s just a mouse, panicking first and thinking later is not such a half-bad idea.

Anxiety traits are no mere artifacts of an earlier age. Anxiety is crucial to marshaling our wits. We could never survive one day in traffic without it, let alone the full range of personal interactions.

Dr Nesse compared the brain's limbic system to a smoke detector that is programmed to deliver 1000 false alarms for every genuine alert. The false alarms are the price of survival. Better to be too anxious.

Now imagine modern man in the supermarket having a panic attack while reaching for a bottle of water. The seriously anxious, it turns out, have hyper-sensitive smoke detectors. The false alarms and the hyper-sensitive in our midst tend to blind us to the fact that a certain degree of anxiety is good, that we would fail to exist as a species without it.

An application of evolutionary biology is Darwinian medicine. For instance, a medical doctor might want to think twice before prescribing something to lower a patient’s temperature. In patients with panic attacks, Dr Nesse has had success once he helps them realize that their response is not necessarily abnormal. Once that happens, often the power of the panic attack dissipates.

The Darwinian Bipolar Advantage

Our behaviors and emotions, according to evolutionary psychiatry, are adaptations the mind has made to recurring situations. In making a Darwinian case for bipolar, it’s easy to imagine highly energetic and productive and creative types having a selective advantage over their more mundane kinfolk. Think of mania lite. Passing on the risk of more serious manifestations was an acceptable trade-off.

I like to contend that it took a crazy person to run into a burning forest and enthusiastically bring a flaming souvenir back to the cave, raving on about the glories of barbeque. I’m sure this individual's reward was summary eviction by an enraged spouse. Ah, the price we have to pay. It’s never been easy being bipolar.

In my version of the story, the two made up and lived long enough to pass on their traits to the next generation, but only after one of them arrived at the concept of putting the meat on a spit rather than holding it bare-handed over the open flame.

Or bipolar could be a lot more elemental. The illness could be an adaptation to changes in the seasons. Think seasonal affective disorder. Think of a very long cycle. (Goodwin and Jamison refer to this in the second edition to “Manic-Depressive Illness.”)

The Darwinian Depression Advantage

But what about depression? Surely, there can be no selective advantage here. Think again. For one, depression may amount to a failure of denial. Depression is when the rose-colored glasses come off, when reality sets in. It opens the way to acceptance, to setting new goals and moving on with our lives.

Also, sometimes it’s helpful to be too depressed to press our luck. If mania is all about daring, depression is about caution. The daring have an advantage in life's ultimate prize, the opportunity to mate. So do the cautious.

Depression also provides an opportunity for regrouping and recouping, not to mention a time of introspection and reflection. Think of depression as an enforced time-out. In its own perverse way, depression may set the stage for needed psychic healing.

As with anxiety and mania, we are talking more benign manifestations. The more virulent versions of depression, it seems, are part of the price we have to pay.


Schizophrenia is far too horrific an illness to see any obvious selective advantage. Yet, the culprit genes have been transmitted from generation to generation, even in Einstein's family. What gives?

First, it is not helpful to look upon schizophrenia as a simple disease. About a hundred suspect genes have been fingered. One of these genes - COMT - has a variation that enhances thought processing in one context but disrupts it in another. Another gene - DISC 1 - helps integrate neurons into the mature brain.

In this context, schizophrenia can be seen as the breakdown in the processes responsible for building and maintaining a complex brain.

Schizophrenia may also be seen as part of a spectrum. At the schizophrenia extreme, the brain is far too active for its own good, characterized by runway thoughts such as psychotic delusions. A lighter version may well be schizotypal personality disorder, characterized by various oddball behaviors and "magical thinking." Tone this down a bit more and we may be talking about eccentrics who think outside the box.

Nancy Andreasen MD, PhD of the University of Iowa describes Einstein as having having schizotypal traits, as well as a son with schizophrenia. Her original enquiry into creativity involved looking for a schizophrenia connection (also citing Newton and James Watson) but very quickly changed to bipolar.

There may be another aspect to "schizophrenia lite." The book, "A Beautiful Mind," chronicles the life of Nobel Laureate John Nash. His breakthrough accomplishments occurred as a young adult, before his outbreak of schizophrenia. But as the book makes clear, there is no way we can describe an apparently healthy John Nash as "normal." Even in a profession notorious for its eccentrics, Nash was very much an outsider.

We tend to think of mental illness as a complete break with reality or rationality, but these breaks don't just happen overnight. Subtle symptoms may manifest many years earlier, what the experts describe as "prodromal" states. Could Nash's "beautiful mind" be attributed to such a state? Who knows?

Working With What We're Stuck With

"Human biology," says Dr Nesse, "is designed for stone age conditions." Or, as Leda Cosmides and John Tooby of the University of California at Santa Barbara put it, "our modern skulls house a stone age mind."

In other words, we are the beneficiaries of a group of genes that did not anticipate the demands of modern living. Were we mere machines with replaceable parts, we could simply send our brains back to the manufacturer for a retooling. Instead, we are forced to work with what we're stuck with.

Dr Nesse cites the example of the eye. Those who champion intelligent design point to the wonders of the eye in support of their theory that creation is way too complicated to be left for chance.

But look closely at the eye, Dr Nesse advises. We have wires running between the lens and where the image is processed. No camera manufacturer would be dumb enough to do that. Plus the eye has a blind spot where the retina meets the optic nerve.

The eye of the octopus, Dr Nesse points out, has a far better "design." Through pure chance, he says, we and practically all the rest of the animal kingdom got stuck with the inferior version.

Scientists are in virtual unanimous agreement on evolution's main points, but evolutionary psychiatry is a speculative enterprise, not capable of definitive proofs. Indeed, a legitimate argument can be made that we are retrofitting psychiatry to conform to evolutionary precepts.

Then again, a much stronger case can be made that our behavior makes no sense without taking evolution into account. Instead of viewing all mental illness as solely destructive, we are forced to consider its advantages. And in looking at the advantages, we find potential in our own worth.

Call it the twenty-first century Darwinian challenge. Our ability to feel on levels deeper and higher than the rest of the population, crippling as it may be, has also given wings to our thoughts, ones that motivated our distant ancestors to climb out of their cozy rock condos in the first place and now seem destined to have us reach for the stars.


Anonymous said...

Just an interesting note about the male peacock's tail plumage: It is, in its environment, excellent camouflage - just as are, (though it wouldn't seem so at first glance) a tiger's stripes. The American artist Abbot Thayer (a painter mostly) invented camouflage, and the colored drawings and notes in his artists' notebooks show that he understood how the bright colors and iridescence of the peacock's feathers could camouflage it in its bright environment. So, while its plumage is, indeed used to attract a mate and may, when fully arrayed and accompanied by strutting and noise-making, make it more vulnerable to predators, when on the ground the tail feathers are still quite sizable and just as bright, but can pass for flashes of light and dark, reflections, etc. which make it excellent camouflage.

John McManamy said...

Hey, Anonymous. That's very interesting. I don't know if I'm remembering this correctly, but here goes: A long time ago, Life Magazine published a photo of a tiger in the tall grass. The commentary to the photo explained that the photographer thought he was shooting just tall grass. He only realized he had shot a tiger when he developed the picture.

So, yes - I very much appreciate your point. Here's another twist:

We start with your point that the feathers make good camouflage. But then a Darwinian arms race breaks out. The males keep producing bigger and more burdensome feathers. These may catch the eye of females, but the sheer weight of the load they carry may make them less able to flee and defend against predators.

I've heard a similar argument regarding elk or moose antlers. Big is good for establishing dominance, but are very problematic when escaping predators. The antlers get caught in branches. Next thing, they are the main course in a wolf buffet.

I just looked up Thayer on Wikipedia. Fascinating.

Anonymous said...

This is an excellent piece. I so enjoy reading everything you write. I read you book in 2 days!! Thank you so much for sharing....Love the personal stories in your book, felt like I was reading about myself.
I read a book called "A First rate maddness uncovering the links between leadership & Mental illness" by Nassier Ghaem. It is a great book & addresses famous leaders such as Lincoln, Churchill, Kennedy & their Bipolar issues & speaks of the advantages they had in leadership because of their illness. Highly recommend it!!


John McManamy said...

Hey, Justawatchingit. So glad you enjoyed this and my book. I was having one of those days, so your post came at just the right time.

Funny you should mention Dr Ghaemi. Check the topic blurb on the inside front page. I first ran into Dr Ghaemi at a conference in 2002, and his insights very much influence my writing. If you enter Ghaemi in the Google search field at the right, you will come up with tons of hits on this blog, including a whole slew of posts I did last year on his eye-opening book.

I couldn't just stop with reporting on the book. I had to do some speculating of my own, including whether President Obama might be "too normal" for the good of the country. My speculating carried me further afield into the writings of Barbara Oakley and "borderpaths."

The two have very different outlooks, but I view the conversation as the unfolding of a dialectic that will never resolve but will endlessly fascinate.


Anonymous said...

Well I just got your book last week & I just discovered your blog recently so I have not read it all (though I do have the potential to read it all in one night!!)I will read it in bits & think about it for awhile. I got this book (first rate maddness) last summer after being diagnoised with MD last Feb. & it helped me to deal with my own judgement of self & the label MD puts on us. I already knew I was different but I agree all knowledge is necessary. All knowledge of self helps in ones awareness. I also try to be the "observer" in my life & I find it helps me to not go down the rabbit hole. For good or bad are illness has shaped how we have perceived the world & yes it is a dangerous gift but one I would never trade for all of those beautiful & profound moments it has helped me to realize. I like the part you said of mania being the daring part & depression the cautious side. Sounds to be like we are pretty well rounded.
I also like in the book how you talk about "Fred" & that before coming into this life the choice you made between being wealthy & the gifts of MD. Well here is my take I call mine now "Wilma" (AKA Flintstones) because I know we have known each other for more than just this life. We been traveling companions for lifetimes. How else could I be accepted in this gene pool unless I had the propensity. Like attract like. Glad I made your day you made mine last week!! Glad to return the favor!

Liz said...

Thank you very much for writing about this topic. I have been struggling for a long time to try and figure out how it is that bipolar disorder was somehow an evolutionary advantage.

This comment of yours really hit home and brought tears to my eyes:
"I like to contend that it took a crazy person to run into a burning forest and enthusiastically bring a flaming souvenir back to the cave"

I know that as a bipolar person I am able to experience a different reality and range of emotions than people who have chemically "balanced" brains. It's helpful to hear an anecdote about how this difference in reality perception can actually make being bipolar useful rather than a burden.

John McManamy said...

Hey, Liz. Very glad the piece gave you insights. I'm a very strong believer that as devastating as our illness may be that we need to appreciate the special gifts. Our perceptions of reality are different. The only reason that is regarded as "wrong" is because we are in the minority.

On my website, mcmanweb, I have a whole bunch of articles that explore this. You might want to start with this one about nonlinear thinking:

From there, at the bottom of the page, you can click on the links to creativity, intuition, and psychic perception.

Also, the at the top and bottom of each article is a "Behavior" link that leads you to a landing page with more articles on our perceptions of reality, such as "Depressed or Thinking Deep."

My whole point to all of them is that once we learn to rein in the extremes in our behavior (we don't want to come across as inappropriate or too weird) it's okay to be who we are and to enjoy it.

I think it's all about finding our social sweet spot. Basically, people like it when we're a bit crazy - ie funny, insightful, entertaining, light up the room. They also like it when we express our feelings and show our empathy and compassion. We may be a bit weird and over-the-top and moody, but they see this as part of the total package and are very happy to have us around.

When they're happy in this way, we are happy. We are connected, not isolated and alone.

Also check out my piece on "Normal - Highly Over-rated." Normal is NOT what we want. We are not ourselves when we act normal. Yes, there are times when it's best to simply blend in with the scenery and not draw attention to ourselves. But this is no way to lead our lives.

I don't think I ever heard anyone say - "Wow, you'll really like So-and-So. He's so normal."

Guess what? I think you've given me the topic for a blog. :)