Wednesday, 30 December 2015

Optical Illusions and the Deception of Desire

I know those two lines are the
same length but the knowing
makes no dent in the illusion
of their difference.

In the Müller-Lyer illusion two lines of equal length are made to look unequal. One explanation of the trick is that our minds interpret the lines as the corners of buildings: the one on the left as an inside corner and the other as an outside corner. Under that interpretation, the one on the left must be further in the distance to us than the one on the right and our perceptual system adjusts it to appear bigger. I’ve read that when those lines are shown to people from the New Guinean highlands – tribes who have never lived inside rectangular houses – they judge them to be the same length as invariably as we judge them to be different. The illusion is culturally dependant

What interests me most, however, is that, like most visual illusions, knowing the truth makes no difference to our perception. We can move one line onto the top of the other, or measure both with a ruler to prove that they are the same, and yet when we look again at the two, one still looks longer than the other. What’s more, neither a psychologist who understood how the illusion works nor a neuro-surgeon who tracked down the exact set of neurons that make the visual mistake would be immune to the deception. A complete knowledge of the illusion does nothing to dissolve the illusion. The one still looks longer than the other. 


Desire often acts in the same way. 

Some of our desires spring from natural appetites and needs: a desire for warmth when we are cold, a desire for food when we are hungry. But the objects of our desires are usually selected for external and cultural reasons. We learn what to desire by imitating the desires of other people. We learn what food tastes good from our parents and friends. We learn what hair-style looks good by watching how our peers respond to each other. We learn what car is cool from marketing campaigns. We learn what jobs are valuable by observing how others value them.

As a result some, perhaps most, desires are illusions. There is nothing inherently “better” about most hair styles (despite what Paul says in 1 Corinthians 11:14!). The car most suited to your needs probably bears little resemblance to the car you are encouraged to buy. The hair and the car are desirable because we see what we might look like if we had that hair or that car through the eyes of imagined others.

We do not always succumb to the illusion. There are conscious and unconscious reasons why we might rebel against our desires, or deny ourselves the pleasure promised by the desire, or for any range of practical reasons not pursue the desire.

And yet, like the Müller-Lyer illusion, the desires themselves are immune to our conscious knowledge. We continue to desire something even when we know that the basis for the desire is flawed.

Let’s follow one example in a little more depth. We are bombarded by images of what a desirable human body looks like. Knowing how the psychological mechanism of desire operates does not change my perception that a particular cultural image of physical beauty would bring more satisfaction in a partner than alternatives. At one level that is ridiculous, for the glamorous ideal of beauty changes with time and culture.

The word “glamorous” originated from a Scottish word meaning a magical enchantment. To say that someone is glamorous is to acknowledge that their appeal is an illusion. There is a glamour over our desires, a veil so powerful that even knowing it is there does not dispel its effect.

At another level the beauty assumption is totally contrary to my experience. Good relationships do not depend on it. Why should they? Neither does good sex depend on it. On the contrary, from my limited experience, the most enjoyable sex does not depend on physical beauty but on mutual enthusiasm. But in this instance, another aspect of desire comes to the fore: from whence comes “mutual enthusiasm” if not from both people desiring each other and desiring each other’s desire?

At some other, less conscious level, however, the illusion remains. I want a girlfriend whom others would affirm as desirable and I perceive this girl or that girl in the light of that desire. I’m attracted to a house in a particular suburb not only because I am consciously aware that it will establish my social status but because I genuinely like the house and the suburb. Liking this girl or that house is totally unaffected by my conscious knowledge of the dynamics of desire.

Necker Cube


In another class of optical illusions, our perception can jump between competing interpretations of an image. A simple example is the Necker Cube on the left. Which face of the cube is in front and which face is behind? You can flip between the two by focusing on either of the inner corners.

A more dramatic example is the train in this animated image, which can be made to move in either direction merely by imagining it to do so.

Such images are ambiguous and what we see depends on what we choose to see.

A similar ambiguity inhabits desire. I noted above that just as the mis-direction of an optical illusion is impossible to dispel, so too the mis-direction of desire. I think it is also true that just as there may be multiple ambiguous interpretations of an optical illusion, so too we often experience multiple ambiguous desires. Sometimes what we desire depends on what we choose to focus on.

Desires are sometimes layered. I desire that house, perhaps because of a deeper desire to impress my colleagues at work, and that may be just an example of an even deeper desire to belong.

Desires sometimes compete. The way we manage personal finances may arise out of a desire to enjoy material possessions now, a desire to save for a secure future, and a desire to use what we have to bless others: desires that ultimately might be mutually-exclusive.

Desires sometimes remain unconscious. We act in order to attain something, but we are unaware of either what we seek or why we seek it.

Add to the mix a type of self-deception that, relying on the ambiguity of our desires, allows us to believe
one interpretation, or act as though we believe it, only by discounting or even disavowing the others.

As a consequence of those layered, competing and unconscious dynamics of desires, there is rarely a clean correlation between how we act and what we desire. Nevertheless, and this is perhaps the point of what I am writing, whether and how we act on our desires can be subjected to conscious choice.

We may not be immune to the deception of desire, but we can occasionally see through the veil and decide to not be enslaved by the desire. It is possible to undermine our self-deception and to behave beyond the illusion.

Maybe this helps to untangle an apparent contradiction in a saying of Jesus. Two of his biographers record Jesus as saying “Whoever wants to be my disciple must deny themselves” (Luke 9:23, Matthew 16:24) and yet they also note that in the next breath Jesus asks “What good is it for someone to gain the whole world, and yet lose or forfeit their very self?” Which is it? Are we commanded to deny ourselves, to give up what is most dear to us? Or are we advised that it serves no good whatsoever to give up ourselves?

One suspects that Jesus has seen through the deception of desire. He knows that gaining everything we desire would not bring the wholeness we seek. On the contrary, coerced by our desires, we lose our very selves. But by questioning our desires, perhaps we can dispel the glamour enough to decide beyond desire. Perhaps by understanding the illusion we can regain our true selves.