Pupil Signals

[Renwein]

Pupil Signals
Pupil dilations and constrictions indicating changes of mood.

When we look closely at a human face we are aware of many expressive details - the lines of the forehead, the wideness of the eyes, the curve of the lips, the jut of the chin. These elements combine to present us with a total facial expression which we use to interpret the mood of our companion. But we all know that people can 'put on a happy face' or deliberately adopt a sad face without feeling either happy or sad. Faces can lie, and sometimes can lie so well that it becomes hard to read the true emotions of their owners. But there is at least one facial signal that cannot easily be 'put on'. It is a small signal, and rather a subtle one, but because it tells the truth it is of special interest. It comes from the pupils and has to do with their size in relation to the amount of light that is falling upon them.

The human pupils appear as two black spots at the centres of the coloured irises and it is common knowledge that these spots are openings that vary in width as the light changes. In bright sunlight they narrow to pinhead size - about two millimeters across - and as dusk falls they widen to perhaps four times their sunlit diameter. But it is not only light that affects the pupils. They are also affected by emotional changes. And it is because emotional changes can noticeably alter pupil size when the light remains constant that pupil size-change operates as a mood signal. If we see something that excites us whether with pleasurable anticipation or with fear, our pupils expand more than usual for the existing light conditions. If we see something mildly distasteful, they contract more then they should in the existing light conditions. These changes normally occur without our knowledge and, since they are also largely beyond our control, they form a valuable guide to our true feelings.

But Pupil Signals are not only unconsciously emitted, they are also unconsciously received. Two companions will feel an added emotional excitement if their pupils are dilating, or an added emotional dampening if their pupils are contracting, but they are most unlikely to link these feelings with the Pupil Signals they are transmitting. It is a 'secret' exchange of signs operating below the level of contrived manners and posed expressions.

A great deal of research has been carried out during the past fifteen years to try and find out how these unsuspected Pupil Signals work. The basic laboratory test has been to show people emotionally exciting pictures and at the same time to record any changes in their pupils, using sensitive apparatus. Great care is taken to ensure that there is no change in the strength of light falling on the subjects' eyes, so that the experimenters can be virtually certain that any pupil dilations or constrictions are due solely to the emotional impact of the various pictures shown.

An early experiment involved showing photographs of human babies to single men and women, married men and women who were not yet parents, and men and women who were parents. The women showed strong pupil dilation when viewing these pictures, regardless of whether they were single, married and childless, or parents. The men, in contrast, showed pupil constriction if they were single or married and childless, but showed strong dilation if they were parents. In other words, the childless human male who coos over someone else's new baby is probably merely being polite, but the female means it. Not until the human male actually has a baby of his own does he start responding with truly sympathetic emotion to other people's infants. The human female, on the other hand, even before she has bred seems to be primed for maternal reactions.

When you look at a picture of a baby, your pupils will change size very slightly.
Whether they dilate or constrict will depend on your sex and your parental status. It has been found (below) that baby pictures shown to single women, married but childless women, and mothers, produced pupil dilation in all three cases. By contrast, single men and married but childless men showed pupil constriction, and only fathers responded with pupil dilation. (After Hess: The Tell-tale Eye).

Sexual reactions have been tested in the same way. Pin-up pictures of naked males and naked females have been shown to both men and women, and the findings are that homosexuals on the whole show a positive pupil response - that is, their pupils enlarge - when they see the naked body of a member of their own sex, while heterosexuals show a strong response to the opposite sex.

One interesting aspect of the sexual tests was that women as well as men found naked bodies very much more exciting than clothed ones. Men, of course, make no secret of this and it is considered quite acceptable for young men to pin up pictures of underclad females on the walls of their rooms. But photographs of underclad men rarely figure in the decorations of the rooms of young women. As a result, a myth has grown up that women, unlike men, are not much aroused by the sight of a naked body of the opposite sex. Unconscious pupil reactions tell a different story.

Both males and females react strongly to photographs of nudes of the opposite sex, when their unconscious pupil reactions are measured. The idea that females are less interested in the naked male then males are in the naked female is refuted by these findings.

Another form of 'deception' was uncovered when liberally-minded people were shown photographs of black males kissing white females. Although all the subjects spoke approvingly of racial equality when questioned on the topic, their pupils split them neatly into two groups - the liberals 'at heart' whose pupils matched their stated beliefs, and the 'merely persuaded' liberals, or perhaps pseudo-liberals, who, despite their praise for racial integration, revealed pinprick pupils when confronted with the black-kissing-white display.

In another experiment, subjects were asked to state food preferences and were then shown photographs of the foods in question while their pupil reactions were monitored. Most people in this test revealed a perfect match between statement and pupil response. The more they said they preferred a food, the more their pupils expanded when they looked at a picture of the food. But a few individuals showed a poor match, which was surprising considering the innocuous nature of the experiment. Who would want to lie about food preferences? The answer came when further questioning was carried out - almost all the food 'fibbers' were dieters on strict regimes but secretly (in some cases secretly even to themselves) still longing for now-forbidden foods. Their reasoned preferences were no longer in tune with their unconsidered preferences.

A similar inconcistency was exposed when a series of pictures of different women were shown to experimental subjects. Among them were photographs of attractive pin-ups and the painting of Whistler's Mother. Needless to say, the old lady was highly rated when subjects were asked for verbal opinions, but she sank dramatically in the preference ratings when the pupil dilations and constrictions were analyzed.

Intriguing as these experiments are, they tell us only what can be discovered in the laboratory, using sensitive apparatus to measure the pupil size-changes. Before we can justifiably call these pupil reactions Pupil Signals, we need to prove that they are in fact detected by onlookers in ordinary day-to-day social contacts using nothing but their own eyes, and that these emotional pupil changes are actually being used as a social communication device. A simple way to demonstrate this is to show a large audience two posters of an attractive girl, identical in all respects except that in one poster the girl has normal pupils and in the other she has her pupils artificially enlarged by over-painting them with bigger black spots. With only this one change, and with the audience unaware of what has been done, all the men present are asked to choose which girl they like the best. When a show of hands for girl 'A' is called for, only a few are raised, but when votes for girl 'B' (the one with the retouched pupils) are requested, a forest of hands goes up. Usually the audience laughs when this happens, because they still do knot know why nearly all the men are choosing the same girl. They know they have been tricked, but they do not know how. The men's response was towards the girl who was 'evidently' stimulated by their presence, because she was dilating her pupils at them. She was 'excited by what she saw', expanded her pupils, and thereby made herself more attractive.
This is one of the reasons why young lovers spend so much time gazing closely into each other's eyes. They are unconsciously checking each other's pupil dilations. The more her pupils expand with emotional excitement, the more it makes his expand, and vice versa.
One experiment tested the pupil reactions of avowed 'Don Juans' - girl-chasers, men who liked to conquer a girl sexually and then move on to another, never forming a lasting, loving attachment with any one girl. These males, when tested, did not show the normal pupil dilation when viewing pictures of attractive girls. They showed a greater pupil response to girls with constricted pupils than to girls with dilated pupils. In other words, they preferred non-loving girls to loving girls. They were wary of girls who might become too clinging and therefore complicate their Don Juan life-style.

Since, in all the examples mentioned, the subjects of the experiments were unconscious of what was happening, either to their own pupils or to those of their companions, it is likely that we are dealing with a basic, inborn response of the human species. This idea is reinforced by tests carried out using schematic eye-spots instead of real eyes. A circle with a spot inside it can be drawn on a sheet of paper and shown to a person whose pupil reactions are being recorded. A single circle-with-spot or a treble - that is, three circles, each with a spot inside - prove to be less effective signs than a pair of eye-spots. Also, with the pair of eye-spots, the subject is more responsive when the spots inside the circles are enlarged, but there is no such increase in reaction when similar 'dilations' occur with the single eye-spot or the treble eye-spots. Apparently, a pair of circles with spots inside them has some special significance for the human animal and makes him react in a way that he cannot control, cannot learn or unlearn, and is quite unconscious of it as it is happening. It is hardly surprising therefore that human babies have generally larger pupils than adults, for babies clearly have a need to muster as much appeal as they can, to ensure that they stimulate the strongest possible caring and loving responses in their parents. Any inborn signal they can emit that makes them unavoidably more lovable will obviously have increased their survival chances - and pupil enlargement appears to be just such a signal.

Finally, it is worth recording that, despite the fact that serious research into the subject of pupils signals has only been carried out during the past two decades, the signal was consciously manipulated in earlier times. Hundreds of years ago, the courtesans of Italy used a drug made from the Deadly Nightshade plant to drop into their eyes in order to make their pupils dilate. This was said to make them more beautiful and so the drug was called 'Belladonna' meaning, literally, 'beautiful woman'. A later example comes from the jade dealers of pre-Revolutionary China, who took to wearing dark glasses expressly in order to conceal their excited pupil dilations when they were handed a particularly valuable specimen of jade. Before this was done, the dilations were consciously watched for by the jade salesmen, as signals of interest and therefore of potentially high prices, but these are isolated examples, and most of the world has gone about its business, dilating and responding to dilations, without any such deliberate techniques.