The initial organization of the brain does not depend that much on experience. Nature provides a first draft, which experience then revises. Built-in doesn’t mean unmalleable; it means organized in advance of experience.
Gary Marcus, The Birth of the Mind, 2004
It takes … a mind debauched by learning to carry the process of making the natural seem strange, so far as to ask for the why of any instinctive human act. To the metaphysician alone can such questions occur as: Why do we smile, when pleased, and not scowl? Why are we unable to talk to a crowd as we talk to a single friend? Why does a particular maiden turn our wits so upside-down? The common man can only say, ‘Of course we smile, of course our heart palpitates at the sight of the crowd, of course we love the maiden, that beautiful soul clad in that perfect form, so palpably and flagrantly made for all eternity to be loved!’
William James, The Principles of Psychology
What Scientific Idea is Ready for Retirement?
Cartesian Hydrolicism
by Robert Kurzban
In the 17th century, René Descartes proposed that the nervous system worked a bit like the nifty statues in the royal gardens of Saint-Germain, whose moving parts were animated by water that ran through pipes inside of them. Descartes’ idea is illustrated in the well-known line drawing that appears in many introductory psychology textbooks that shows a person puzzlingly sticking his foot in a fire, presumably to illustrate Descartes’ idea about hydraulic reflexes.
Three centuries on, in the mid-1900’s, the detritus of the hydraulic conception of behavior, now known to be luminously wrong, was strewn about here and there. In the scholarly literature, for instance, there were traces in Freud’s corpus—catharsis will relieve all that pressure. Among the Folk, hydraulic metaphors were—and still are—used to express mental states. I’m going to blow my top. Having written an essay for Edge today, I feel drained.
There is, to be sure, still plenty of debate about how the mind works. No doubt even on the pages of this year’s Question there will be spirited discussion about how well the brain-as-device-that-computes notion is doing to advance psychology. Still, while the computational theory of mind might not have won over everyone, the hydraulic model Descartes proposed is dead and buried.
Well, dead anyway. Buried… maybe not. (And, to be sure, hydraulics is, as it turned out, the right explanation for a pretty important (male) biological function; just not the one Descartes had in mind.) The metaphors that recruit the intuition that the mind is built of fluid-filled pipes, along with junctions, valves, and reservoirs, point to the possibility that Descartes was drawn to the notion of a hydraulic mind not only because of the technology of the day, but also because there is something intuitively compelling about the idea.
And, indeed, Cartesian hydraulics has been revived in at least one incarnation in the scholarly literature, though I doubt it’s the only one. For the last decade or so, some researchers have been advancing the notion that there is a “reservoir” of willpower. You can’t have an empty reservoir, the theory goes, in order to exert self-control—resisting eating marshmallows, avoiding distractions, etc.—and as the reservoir gets drained, it become harder and harder to exert self-control.
Given how wrong Descartes was about how the mind works, it’s pretty clear that this sort of idea just can’t be right. There have recently been a number of experimental results that disconfirm predictions made by the model, but that’s not why the idea should be abandoned. Or, at least, the data aren’t the best reason the idea should be abandoned. The reason the idea should be left to die is the same reason that Descartes’ idea should be: Although the mind might not work just like a digital computer—no doubt the mind is different from your basic PC in any number of important ways –we do know that computation of some sort is much, much more likely to be a good explanation for human behavior than hydraulics.
People will disagree about whether Planck was right about the speed of scientific change. Psychology, I would argue, has a couple of handicaps that might make the discipline more susceptible to Planck’s worries than some other disciplines.
First, theories in psychology are often driven by—indeed, held captive by—our intuitions. I’m fond of the way that Dan Dennett put it in 1991 when he was talking about the (also luminously wrong) idea of the Cartesian Theater, the dualist idea that there is a “special center in the brain,” the epicenter of identity, the One and True Me, the wizard behind the curtain. He thought this notion was “the most tenacious bad idea bedeviling our attempts to think about consciousness.” Human intuitions tell us that there’s a special “me” in there somewhere, an intuition that serves to resurrect the idea of a special center over and over again.
Second, psychologists are too polite with each other’s ideas. (Economists, for example, in my experience, don’t frequently commit this particular sin.) In 2013, a prominent journal in psychology published a paper that reported the results of attempts to replicate a previously published finding. The title of the article was, before the colon, the phenomenon in question and then, after the colon: “Real or Elusive Phenomenon?” The pairing of real versus elusive as opposed to nonexistent highlights that it’s considered so rude to suggest that a result was a false positive—as opposed to something that’s simply hard to replicate—that people in the field won’t even say out loud that prior work might have been pointing to something that isn’t, really, there.
Of course intuitions interfere with theoretical innovation in other disciplines. No doubt the obviousness of the sun going around the Earth, bending across the sky each day, delayed acceptance of the heliocentric model. Everyone knows the mind isn’t a hydraulic shovel, but it does feel like some sort of reservoir of stuff gets used up just as it does feel like the sun is moving while we stay put.
Still, it’s time that Cartesian hydrolicism be put to rest in the same way that Cartesian dualism was.
About Robert Kurzban
Psychologist, UPenn; Director, Penn Laboratory for Experimental Evolutionary Psychology (PLEEP); Author, Why Everyone (Else) is a Hypocrite
Piece from Doug Kenerick’s blog on Psychology Today: http://bit.ly/1iLn5RP (where I found this video).
Much as a word exists as a sound, a set of marks on a page, and a metaphor, nature and nurture are diverse conceptual frameworks for a single set of phenomena.
Andrew Solomon, Far from the Tree, 2012
Using the definition of selfishness and altruism that biologists use, a loving and self-sacrificing mother is acting selfishly, while a drug addicted mother who starves her children to give all her money to her dealer is an altruist (i.e., she is lowering her own fitness in a way that increases a nonrelative’s).
John Tooby, Genic Selection and Adaptationism: Are We Moving Forward or Back?, Edge.org
Paul Bloom talking in the context of his Annual Review of Psychology article “Religion, Morality and Evolution.”
…all of DNA is a twisted rope ladder let down from heaven to draw us up from the abyss of not-being. We do not lift a finger without three kinds of information: the information we are getting from our senses at the moment; the information we have gotten from our senses in the past; and the information our ancestors have acquired since life began on Earth–that is, the information that is represented by genes themselves. Evolution is learning. Species store learning in chromosomes the way individuals store learning in their brains and societies store learning in books.
Jonathan Weiner, Time, Love, Memory, 1999
When I exercise, I choose to run outside. It could be 100 degrees or 35 below zero and I will still lace up and hit the pavement. I avoid gyms because I am convinced that regular time spent outside is good for me. When I sit inside or stand behind a counter all day, I cringe at the thought of wasting even 30 minutes of my breath in a gym; I gulp my breaths, and the finest air is outside.
That being said, I’m not a hardcore outdoors person. I like living in cities with lots of people, opportunities, ideas and 10pm happy hours. I have no desire to live on a farm. I take to heart the words of Jim Gaffigan, who quips, “The happiest camper is the one leaving the campsite.” When I’m outdoors, I love the sights and smells of plants, animals and freshwater, but camping to me feels a lot like chores during valuable free time. I escape outside, but I live in a city.
There’s something to be learned from this feeling toward natural environments. For much of human history, our ancestors lived and died surrounded by green environments. Our bodies and our minds are built from copies of their surviving genes, so we are prepared for those same kinds of environments. The steel and concrete worlds that many of us inhabit now are mismatched with our tendency toward biophilia, or our affinity to life in its natural form.
Now, without forsaking civilization for the life of a hunter-gatherer, or without tearing down all the buildings and ripping up the roads, how can we use this supposed affinity for green to better our lives? Is it possible to both live in a city and experience the natural environment?
I think so. Live near green space. Fight for its development or against its destruction. Here’s why.
New research from Mathew White and his colleagues sheds light on the psyvchological benefits of green space. Generally, these researchers are interested in population level estimates of well-being. Because much research focuses on factors associated with negative outcomes, these researchers wanted to know what is associated with flourishing. They asked a simple question :
Does living near urban green space contribute to psychological well-being compared to other factors?
Cross-sectional research (i.e., snapshots of a population at one time) suggests that it does, but that research is confounded by time-stable characteristics, namely, personality. It could be that happy people move to areas where there is a lot of green space. To control for this, White and company analyzed longitudinal data of over 10,000 people from an 18-year panel survey, the British Household Panel Survey. They were able to compare the self-reported psychological health of the same people at different points in time alongside other known contributing variables such as education, employment, marriage and local crime.
How did they know people lived near green space?
Generalized Land Use Database (GLUD)
Lower Layer Super Output Areas (LSOA)
Combined green space and gardens
Only urban residents
How did they determine the mental health of 10,000 people?
12-item General Health Questionnaire (GHQ)
How did they determine “well-being?”
“How dissatisfied or satisfied are you with your life overall?”
What did they control for?
English Indices of Deprivation
Area-level data were distributed to an individual’s BHPS profile.
What did they find?
For 10,000+ people in England, the average score on the GHQ was 1.92 with a margin of error of ± 0.02 points. For every 1% increase in green space, there was a 0.0043 decrease in GHQ.
The average response for life satisfaction was 5.2 with a margin of error of ± 0.01 points. For every 1% increase in green space, there was a 0.0043 increase in self-reported life satisfaction.
To put this into perspective, people in this population lived in areas composed of, on average, 64% green space. Living in areas composed of 81% green space (1 standard deviation above the average) compared to living in areas composed of 48% green space (1 standard deviation below the average) was associated with a 0.14 point reduction in scores on the GHQ and a 0.07 increase in life satisfaction.
The benefits of the chosen analysis allowed for comparison to other factors associated with mental health and well-being. Using the same comparisons between living in areas with green space 1 standard deviation above and below the average amount, the reductions in scores on the GHQ were:
The associated increases in life satisfaction were:
These effects aren’t large, but they are meaningful considering that no correlations with were found between the GHQ nor life satisfaction and living in areas with lower crime rates or in households with higher incomes.
Since not all potentially influential factors were controlled for in the analysis, causality cannot be assumed. These finding should be considered in the context of other research on the effects of green space on well-being. I’ve written on some of this research before, and I hope to tackle more of it in the future. Visit here for another great blog on this topic.
Now, when you get a chance, go outside. It’s good for you.
References
White, M. P., Alcock, I., Wheeler, B. W., & Depledge, M. H. (2013). Would you be happier living in a greener urban area? A fixed-effects analysis of panel data. Psychological science, 24, 920-928.
A lot of the good battles have been fought over the tenets of evolutionary psychology, but I think EP still doesn’t hold the weight it ought to. If you meet a scientist who claims to be an evolutionary biologist, you may very well be curious enough to ask her what she studies in evolutionary biology. Does she investigate questions in embryology or perhaps foraging behavior? In fact, if she never claimed to be an evolutionary biologist, rather a biologist interested in amphibian development or gopher foraging behavior, you would likely assume she understands evolutionary theory even if she doesn’t employ it regularly in her studies.
*A trait or behavior that is evolutionarily functional is not necessarily moral or ethical. I’m not advocating maxmizing fitness as a moral framework.
Naive Scientist 