All of us, even postmodern philosophers, are naive realists at heart. We assume that the external world maps perfectly onto our internal view of it—an expectation that is reinforced by daily experience. I see a coffee mug on the table, reach for a sip and, lo and behold, the vessel’s handle is soon in my grasp as I gingerly imbibe the hot liquid. Or I see a chartreuse-yellow tennis ball on the lawn, pick it up and throw it. Reassuringly, my dog appears to share my veridical view of reality: she chases the ball and triumphantly catches it between her jaws.
That there should be a match between perception and reality is not surprising, because evolution ruthlessly eliminates the unfit. If you routinely misperceive or even hallucinate and act on those misapprehensions, you won’t survive long in a world filled with dangers whose avoidance requires accurate distance and speed assessments and rapid reactions. Whether you are diving into rocky waters or driving on a narrow, two-lane road with cars whizzing by in the opposite direction, small mistakes can be lethal.
You probably believe that your eyes register high-fidelity information about the absolute size, speed and distance of visible objects and that you respond based on these impartial data. But although we build robots in this manner—equipping them with sensors and computers to plumb the metric properties of their environments—evolution has taken a more complex route.
As psychologists and neuroscientists have discovered over the past several decades, our consciousness provides a stable interface to a dizzyingly rich sensory world. Underneath this interface lurk two vision systems that work in parallel. Both are fed by the same two sensors, the eyeballs, yet they serve different functions. One system is responsible for visual perception and is necessary for identifying objects—such as approaching cars and potential mates—independent of their apparent size or location in our visual field. The other is responsible for action: it transforms visual input into the movements of our eyes, hands and legs. We consciously experience only the former, but we depend for our survival on both.
When driving in the mountains, have you ever noticed a discrepancy between the slope described on the yellow road sign and your sense that the incline is actually much steeper? Psychologist Dennis R. Proffitt of the University of Virginia and his then graduate student Jessica Witt did. Being scientists and not philosophers, they designed an experiment to find out why. Proffitt and Witt stood at the base of hills on campus and asked passing students to estimate their steepness in two ways. Subjects had to align the diameter line on a flat disk to the slant of the hill. They also were asked to place the palm of one hand on a movable board that was mounted on a tripod and then, without looking at that hand, to adjust the board’s slant until they felt it matched that of the hill.
In the first part of the test, which relied on visual cues alone, subjects badly overestimated, interpreting a 31-degree slant as a much steeper, 50-degree one. But when people’s eyes were guiding their hands, subjects judged accurately, tilting the board an appropriate amount. Perhaps even more striking was the finding that people’s tendency to overestimate on the strictly visual part of the test increased by more than a third when they had just run an exhausting race—but the hand estimates were unaffected. The same discrepancy occurred when subjects wore a heavy backpack, were elderly, or were in poor physical condition or declining health.
In another variant of the experiment, Proffitt had subjects stand on top of a hill on either a skateboard or a wooden box the same height as the skateboard. Participants were instructed to look down the hill and judge, both visually and manually, its grade. They were also asked how afraid they felt to descend the hill. Fearful participants standing on the skateboard judged the hill to be steeper than did the braver souls standing on the box. Yet the visually guided action measurement was unaffected by fear.
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Add CommentIt could explain some peoples choice of marriage partner and how you can go to bed with a gorgeous woman and wake up with a dog.
Reply | Report Abuse | Link to thisWonderfully simple experiments reinforce what most (educated) people already knew... and summed up nicely in the last paragraph of the piece.
Reply | Report Abuse | Link to thisThe human organism is a wonderfully evolved whole and our perceptions of "reality" are by necessity subjectively serving its needs, whether we are aware of them... or most likely... not.
The conscious brain's activity is but a drop in a very large bucket of neural activity, where the heavy lifting occurs. The insight of these experiments... along with mountains of other eevidence, renders the notion of "free will" absolutely moot.
Spin-oza -
Reply | Report Abuse | Link to thisInteresting comment. However, I'd be interested in understanding more of your perception regarding "renders the notion of 'free will' absolutely moot."
Thanks.
I would disagree - it seems to me that this article makes manifest that we make free will choices ("The hill is too steep to climb, I will go around") based on more information than objective observation would provide.
Reply | Report Abuse | Link to thisFor instance, in the hill that is "too steep"; while, objectively, I know it to be less steep, I also know that my bum knee is acting up, and that this hill is known as "rattlesnake hill" around here for a reason.
It doesn't negate free will, it stresses that objective reality - that which can be perceived - is lacking enough data to make a self serving decision.
Another way to look at this is to say, objectivity is overrated.
This is another instance that we should not be surprised about but we are when it we find it happens to us.
Reply | Report Abuse | Link to thisEvery organism it would seem builds a perception of reality that is flexible and benefits the organism (too much data, limited sensors and processing time).
Not a surprising statement until you realize it means you also. This is no trippy mind-bender either, YES you live in a virtual perceived world of your making . . but NO that perception difference does not change reality and a too big a gap at the wrong time can be quite deadly . as reality always trumps your perception of it no matter how hard you wish.
Our system is build for speed and immediate survival . . When accuracy is needed we must ALL assume our first impression is wrong and take steps to take the time and effort to discover the inaccuracies and be ready to conclude that we where wrong.
Science itself is all about finding the new, but also understanding humans make errors ( a default state) and making sure to minimize, cross check and self correct them.
The world we perceive is an illusion! It is, as the yogis say, MAYA.
Reply | Report Abuse | Link to thisAlternatively, perhaps our perception of physical reality is a function of our objective external assessments and our internal subjective state. Our response to external conditions must account for our transient internal capabilities to best ensure success. We are not likely to succeed in our current physical challenges if we approach them based on yesterday's fully rested and nourished condition rather than our current exhausted state.
Reply | Report Abuse | Link to thisFinally. An explination to how our parents walked to school every day uphill both ways!
Reply | Report Abuse | Link to thisIC2e... since this is not a post on the illusion of free-will, in the contra-causal sense... i "will" not post volumes on the evidence and observations negating such an absurd premise. It should be clear however, that every thing about our selves is naturally caused and determined: genetics & biochemistry (including neuronal development and function). It should also be without question that our minds and physical brains are the same: there is not, nor has their ever been, a "Ghost in the Machine". Put another way, we cannot be the "cause of ourselves" in the exercise of unfettered (supernatural) FW.
Reply | Report Abuse | Link to thisEven though we are full caused & determined "causal agents" we, like all animals must by necessity "choose" among alternatives for either survival or to meet the hierarchy of needs we perceive any any given time. As long as we are not coerced, we may exercise common parlance " FW, but not free will that is beyond the scope of our evolved natural being. Thus, no FW exists in a supernatural or contra-causal sense... nor has it ever been demonstrated.
Does the serial murderer, addict (take your pick), pathologic liar (uh, theres' a genetic basis for that), anorectic or morbidly obese... etc. ad nauseum, freely choose to pursue such self-destructive, maladaptive behaviors? Did you choose the time and place of your birth, your parents... and whether or not you are afflicted with Trisomy 21, craniosynostosis, autism, Fragile-X, schizophrenia. Alzheimer's... etc.?
Read the pioneering work of LIbet or Pasqual-Leone... or the works of such minds as Dennet, Flannagon, Strawson, Pereboom, Wegner... or icons such as Darwin, Einstein, Russell, Spinoza, Schopenhauer, Voltaire, among others... all of whom reject such fantasy.
The evidence from genetics - proteinomics... and neurobiology have pulled away the curtain from the alleged Wizard of Free Will... in the Illusive Land of Oz.
Cheers to All.
The Unified Theory of the Universe by Joseph Rubino(CWRU)September 22, 1999. Thinking is universal(creation itself if you will). The shortcoming is the language which is only the form of verbalization of thinking. Need I add all human endeavor. Explanation: The contribution of Western theoretical science to the world has shown how nature works: the discovery of atomic structure, space, DNA advances,etc. Their application and the ability to manipulate the workings of Nature(such as gene therapy, cloning, etc.)have unimaginable(hopefully positive)consequences for the present and future of man and civilization itself. However can we ever say why nature manifests itself the way it does? i.e. why the proverbial oak seed grows into a tree? Science can only observe its structure, even manipulate, but perhaps can never explain why it must become a tree: "And the parts of a candle, successively melting, turn to flame, and give us both light and heat. These and the like effects we see and know; but the causes that operate, and the manner are produced in, we can only guess and probably conjecture."(John Locke in The English Philosophers from Bacon to Mill, edited by Edwin A. Burtt, Random House, 1939, p.386.) The same applies for the entire observable universe and all things in it. I suggest it may be the "Universality of Thinking" which also transc ends space and time itself as well as the duality of God(s) and creation present in the Middle Eastern and Western tradition. Professor Hawking in his book A Brief History of Time says:"However, if we do discover a complete Theory, it should in time be understandable in broad principle by everyone, not just a few scientists. Then we shall all, philosophers, scientists and just ordinary people, be able to take part in the question of why it is that we and the universe exist."
Reply | Report Abuse | Link to thisThis is a beautifully written article. I love the very last paragraph that states what it is to be human. Many people would assume that one only makes excuses to improve others outlook on them. The idea that we do it to protect our self against self-depreciation is new to me and fascinating.
Reply | Report Abuse | Link to thisAfter reading this and some of the experiments constructed, I immediately remembered watching a show about how we percieve colors to be different based on angles and shadowing. Illusions and our imagination play big roles in perception as well.
Reply | Report Abuse | Link to thisAlternatively maybe you didn't marry that person based on looks maybe the way they did thier makeup, or the way their body looked when you met them is what attracted you to them. Coming from personal experience when you date the same person for a while you tend to get comfortable around them therefore you let yourself go not looking as attractive as you once did to your partner
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