"I GOT PEOPLE LOOKIN' CRAZY" LIL W.E.B.
Humans are natural people watchers, and most of the time we look at faces and eyes. The focus of another person's gaze is a very powerful signal for us to look in the same direction. Magic Johnson was a great basketball player because he used the "no look" pass: he could pass the ball to a teammate without taking his eye off his opponent. He could control his gaze to hold the other player's attention and not betray with his eyes where he was about to pass. More impressive was his ability to look toward one teammate and then pass to a completely different person, sending the defender on the opposite team in the wrong direction.Our difficulty in ignoring the gaze of another person shows what an important component of human social interaction it is. They say that the eyes are the window to the soul. I don't know about souls, but eyes are a pretty good indicator of what someone may be thinking. You can observe this yourself the next time you are standing in line at the supermarket checkout. Just watch the rich exchange of glances between people. It's remarkable that we are often so unaware of how important the language of the eyes is. This is one reason why it is so unnerving to have a conversation with someone who is wearing sunglasses and we cannot monitor where they are looking. Police officers wear mirrored sunglasses to intimidate suspects for this very reason.
This sensitivity and need to see another's eyes is present from birth. Newborn babies prefer that we look them in the eye. Even though their vision is so poor that they would qualify for disability insurance, they can still make out the eyes on a face, and they prefer the faces of adults whose gaze is directed toward them. Since they have little experience of people-watching, this strongly suggests that gaze-watching is another process built in at birth. People in love stare at each other, and parents and babies spend long periods engaged in mutual staring. If you look into the eyes of a three-month-old, the baby will smile back at you. Look away and the smiling stops. Look back and the baby smiles again. Mutual gaze turns the social smiling on and off. Not surprisingly, it works in the other direction. If the baby stares, parents smile. They really do have us wrapped around their little fingers.
Gaze is part of a general range of social skills called joint attention. When humans interact socially, they do so by sharing the same focus of interest. Whether it is discussing a topic, watching a basketball game, or admiring a painting, we can join in a combined effort to examine the world. Joint attention is not uniquely human; many animals use it to extend their range of potential interests or threats. Like meerkats, who watch each other for the first sign of danger, animals can gain the benefit of watching others watching the world...
Supersense: Why We Believe in the Unbelievable. Hood, p.115-116
Studies of child development reveal that we become much more sensitive to other people's gaze as we get older. Gaze is such an important channel of communication that we automatically pay attention to it. In fact, we can't ignore it. That's why having a conversation with someone who repeatedly breaks fixation or glances off is so annoying: they are thwarting our attempts to read their thoughts based on their gaze. So gaze is crucially important to us. When someone stares at us, it directly stimulates the emotional centers deep inside our brain. Staring is not a passive act but an active event that affects us emotionally.
The amygdala and ventral straitum are the emotional structures deep within the brain that fire during social exchanges. They give us the feelings we experience during social interactions. Direct gaze at a distance is fine for recognizing people, but direct gaze close up can make us very uncomfortable. If it's coming from a lover, direct gaze makes your heart pound and releases butterflies in your stomach. If it's coming from a stranger, your mind races (What does he want with me?). That's why no one stares at other people inside elevators. We prefer to look at the ceiling or floor rather than at each other. We are too close for comfort.
Children, on the other hand, have to be told not to stare. As we saw earlier, babies look at eyes from the very beginning, but with age, we become more attuned to gaze. As we approach adulthood, we need to be able to figure out friend or foe, and so we increasingly learn the subtleties of social interaction and the meaning of a glance. We also become more self-conscious about the others around us, and our need for social approval intensifies. Anyone who has been to a party of adolescents cannot fail to notice the flurry of exchanged glances between the two sexes. These fledgling adults are embarking on the first stages of intimacy, and these early steps involve reading the language of the eyes.
...
The sense of being stared at reflects a common concern about being observed and monitored. George Orwell describes a paranoid world in his classic novel 1984, in which every action and belief of the citizens is controlled by the thought police overseen by the eyes of Big Brother. We tend not to engage in crime when we are being watched. For obvious reasons, we prefer to remain undetected. That's part of the thrill of shoplifting by those individuals who steal items they can readily afford. The excitement is the reward, not the actual object. If we are being watched, we generally conform to social rules. People even become overtly social and more cooperative when they know they are being observed.
Have you ever felt the pang of guilt when you have done something wrong and then wondered whether someone saw you doing it? It doesn't have to be a real person watching you. For example, honesty boxes depend on the virtue of the people to own up and pay for something if they have used it. Typically, these are the boxes in staff rooms and clubhouses that rely on members to make a fair contribution toward the cost of something, usually a hot drink. They generally don't work that well unless there is someone watching the partakers. In one study, researchers posted either a set of human eyes or a picture of flowers above the honesty box for coffee and tea. On average, people paid almost three times more into the honesty box during the weeks when a picture of staring eyes was posted compared to the weeks when a picture of flowers was presented, even though there was no difference in how many cups of tea or coffee were poured. The eyes made people feel guilty about not paying for their drinks.
Sometimes the thought of someone watching us from beyond the grave is enough to make us behave ourselves. For example, students found they had the option to cheat on a computer-based exam when, every so often, the computer "accidentally" gave away the correct answer. In fact, the experimenters had deliberately programmed this to happen because they were really interested in whether participants would cheat by using this information as their answer or behave honestly on the exam. To put the students in the right frame of mind, an assistant casually told them before the test that the exam room was said to be haunted by a former student who had died there. Exam results showed that students who had been told the ghost story were less likely to cheat compared to students given no such story. Our sense of honesty is arguably policed by our feelings of guilt. Part of the guilt comes from the anticipated social disapproval we believe we would experience if we were found to be breaking some rule. Students who believed that a former student might have been present in the exam room were less willing to cheat.
This guilt trip theory has been used to explain why we so readily believe in an afterlife. The psychologist Jesse Bering thinks that the belief in ghosts and spirits may have evolved as a mechanism designed to make us behave ourselves when we think we are being watched. A guilty conscience works because it polices the way we behave, and if it can be easily triggered by the sense of others watching us, then we are more likely to act in a way that is for the benefit of the group. In the same way that students are less likely to cheat when told a ghost story, if we believe the ancestors are watching us, we are more likely to conform to society's rules and regulations. Such a way of thinking, being advantageous to the group, would be likely to be passed on from one generation to the next...assuming the presence of others could be a good evolutionary strategy to always be on the lookout for potential enemies. And if we are hardwired to assume the presence of agents and spirits in the world, even the slightest example of a pattern that could be a face or a pair of eyes will readily be seen as such. Any bump in the night could be another person.
Supersense: Why We Believe in the Unbelievable. Hood, p. 229-230, 232-234.
Consider this passage from Barabara Smuts's "What Are Friends For":
"Alex stared at Thalia until she turned and almost caught him looking at her. He glanced away immediately, and then she stared at him until his head began to turn toward her. She suddenly became engrossed in grooming her toes. But as soon as Alex looked away, her gaze returned to him. They went on like this for more than fifteen minutes, always with split second timing. Finally, Alex managed to catch Thalia looking at him."
Smuts suggests that Alex and Thalia could be two novices at a single's bar. In fact, this description comes from her field notes of two East African baboons beginning a courtship. It could have been lifted straight out of a scene from Sex in the City, although I would guess that a woman suddenly grooming her toes in public might be considered a bit of a turn-off in downtown Manhattan. (Supersense: Why We Believe in the Unbelievable.)
"Alex stared at Thalia until she turned and almost caught him looking at her. He glanced away immediately, and then she stared at him until his head began to turn toward her. She suddenly became engrossed in grooming her toes. But as soon as Alex looked away, her gaze returned to him. They went on like this for more than fifteen minutes, always with split second timing. Finally, Alex managed to catch Thalia looking at him."
Smuts suggests that Alex and Thalia could be two novices at a single's bar. In fact, this description comes from her field notes of two East African baboons beginning a courtship. It could have been lifted straight out of a scene from Sex in the City, although I would guess that a woman suddenly grooming her toes in public might be considered a bit of a turn-off in downtown Manhattan. (Supersense: Why We Believe in the Unbelievable.)
"Why Do We Share So Many Physical, Physiological, Psychological, Behavioral, And Social Traits With Animals, Particularly Primates? If We Aren't Animals, Why Are So Many Of The Traits That We POSSESS Found In Rudimentary Form In Other Animals, Especially Primates?... The Precursors To These Psychological And Behavioral Traits Can Be Found In Our Non-Human Primate Cousins, The Great Apes...All Of Our Mental And Physical Adaptations (Traits) Can Trace Their Origin To More Rudimentary Forms In Other Animals, Especially Primates." -PeeGeeBeeDee (ME. I'm Quoting Myself.)
This Is In Reference To Catching Another Person Staring At You And That Person Looking Away Out Of Embarrassment Or Shyness Or Not Wanting To Be Caught Looking At You. This Primitive And Underdeveloped Form Of Self-Consciousness Is Found In Primates. (FEMALES HAVE ALWAYS STARED AT ME BECAUSE THEY'VE BEEN ATTRACTED TO MY FACIAL FEATURES. I GET TIRED OF IT NOWADAYS.)
This Is In Reference To Catching Another Person Staring At You And That Person Looking Away Out Of Embarrassment Or Shyness Or Not Wanting To Be Caught Looking At You. This Primitive And Underdeveloped Form Of Self-Consciousness Is Found In Primates. (FEMALES HAVE ALWAYS STARED AT ME BECAUSE THEY'VE BEEN ATTRACTED TO MY FACIAL FEATURES. I GET TIRED OF IT NOWADAYS.)
Reading is
to the mind what exercise is to the body and is such an ordinary and
essential activity that we think little about the actual physical task
of reading words. Even if you are reading this book the way Samuel
Goldwyn used to read - "part of it, all the way through" - you are
nonetheless focusing for extended periods of time on a string of black
and white letters that are probably an arm's length away from your eyes.
As your eyes flit from word to word, they remain intently focused on
the page. Sometimes when I am engrossed in a really good book, I lose
conscious sense of my body and the world around me for hours at a time.
But staring at words or anything else so close to your face for hours
isn't natural. Writing was first invented about 6,000 years ago,
printing presses were invented during the fifteenth century, and it was
not until the nineteenth century that it became commonplace for an
average person to spend long hours reading. Today, people in developed nations spend many hours staring intently at computer screens.
All of this focusing brings many benefits, but it may come at the cost of poor vision.
If you are nearsighted, you have no problem focusing on anything close
up, like a book or a computer screen, but everything distant, usually
beyond 2 meters (6 feet), is blurry. In the United States and Europe,
nearly a third of children between the age of seven and seventeen
become nearsighted (myopic) and need glasses to see properly; the
percentage of myopic people is higher in some Asian countries. Myopia is so common that wearing eyeglasses is utterly ordinary and even fashionable. Yet the evidence suggests that being nearsighted used to be very rare. Studies
from all over the globe indicate that rates of myopia are less than 3
percent among hunter-gatherers and in populations that practice
subsistence agriculture. In addition, myopia among Europeans used to be
uncommon except among the educated upper classes. In 1813, James Ware noted that "among
the Queen's Guard many were myopic, while of the 10,000 footguards less
than a half dozen were myopic." In late-nineteenth-century Denmark, the
incidence of myopia among unskilled laborers, seamen,and farmers was
less than 3 percent but was 12 percent for craftsman and 32 percent for
university students. Similar shifts in the prevalence of myopia have
also been documented in hunter-gatherer populations who transitioned
to Western lifestyles. On such study from the 1960s tested eyesight
among Inuits on Barrow Island, in Alaska. Although less than 2 percent
of the elders had even mild myopia, a majority of the young adults and
schoolchildren were nearsighted, some severely. Evidence that myopia is a
modern disease makes sense because it is highly probable that being
nearsighted was a serious disadvantage until recently. In the old days,
people with poor distance vision probably were less able to hunt animals
or gather food effectively, and they were less capable of spotting
predators, snakes, and other perils. People with genes that contributed
to myopia probably died younger and had fewer children, keeping the
trait infrequent.
Nearsightedness
is a complex trait caused by many interactions among a large number of
genes and multiple environmental factors. However, since people's
genes haven't changed much in the last few centuries, the recent
worldwide epidemic of myopia must result primarily from environmental
shifts. Of all the factors identified, the most commonly identified
culprit is close work: intent focusing for long periods of time on
nearby images such as sewing and words on a page or screen. One study of
more than a thousand Singaporean children found that those who read
more than two books a week were three times more likely to have strong
myopia (after controlling for sex, race, school, and their parents'
degree of myopia). Some studies, however, have found that youngsters who
spend less time outside are more likely to get myopia, regardless of
how much they read. Therefore, a related but more important cause may be
a lack of sufficiently intense and diverse visual stimuli during
childhood and adolescence. Additional factors whose causal roles are
not as well supported but that merit further study include diets rich
in starch and early adolescent growth spurts.
To
investigate what factors cause myopia and reevaluate how we treat the
problem, let's first consider how the eye normally works to focus light.
The process of focusing involves two main steps, summarized in figure
28. The first step happens in the cornea, the transparent outer covering
of the front of the eye. Because the cornea is naturally curved like a
magnifying glass, it bends light beams, redirecting them through the
pupil and onto the lens. The next step, fine focusing, occurs in the
lens, a transparent disk the size of a shirt button. Like the cornea,
the lens is convex, which enables it to focus light coming from the
cornea onto the retina, at the back of the eyeball. There, specialized
nerve cells turn light into a stream of signals that are sent to your
brain and transformed into a perceptible image. However, unlike the
cornea, the lens can change its shape to alter its focus. These shape
changes are achieved by hundreds of tiny fibers that suspend the lens
behind the pupil. A normal lens is very convex, but the fibers are like
springs that constantly pull on the lens, flattening it like a
trampoline. In this flattened state, the lens focuses light from distant
objects onto the retina. However, in order to focus light beams from
relatively larger nearby objects onto the retina, the lens needs to
become more convex. This adjustment (termed accommodation) occurs
when the tiny ciliary muscles that attach to each fiber contract,
lessening the tension placed on the lens, allowing it to return to its
natural, more convex shape. In other words, while you are reading these
words, hundreds of tiny muscles are firing in each eyeball to slacken
the fibers and keep your lenses curved, thereby focusing light from the
nearby page or screen on your retinas. If you look up and gaze into the
distance, those muscles will relax, and the fibers will tighten,
flattening the lens so you can focus on faraway objects.
Comin' Up Showt! "the focus point of the flattened lens falls short of the retina. As a result, everything distant (usually beyond 2 meters, or 6 feet) is out of focus, sometimes dreadfully." |
Many
hundreds of millions of years of natural selection have perfected the
eyeball. Its focusing system usually works so well that most of us take
clear vision for granted. But, as in any system with much complexity,
small variations can impair function, and nearsightedness is no
exception. Most cases of nearsightedness occur when the eyeball grows too long, as figure 28 depicts.
When this happens the lens can still focus on nearby objects by
contracting the ciliary muscles, which allows the lens to become more
convex. However, when someone with an overly long eyeball tries to
focus on a distant object by relaxing the ciliary muscles, the focus
point of the flattened lens falls short of the retina. As a result,
everything distant (usually beyond 2 meters, or 6 feet) is out of focus,
sometimes dreadfully. Unfortunately, people with myopia are also at
greater risk of other eye problems, such as glaucoma, cataracts,
detached retinas, and retinal degeneration.
One might suppose that a problem as widespread and as important as myopia would be better understood, but
the mechanisms by which prolonged close work or a lack of outdoor
visual stimuli can cause eyeballs to grow too long are still uncertain. One
longstanding hypothesis is that hours of focus on nearby objects
elongate the eyeball by increasing pressure inside the eye. The
hypothesis goes as follows: When you staring at something close (like
this page), the ciliary muscles have to contract continuously and other
muscles rotate the eyeballs inward (converge) to maintain
binocular vision. Because the ciliary and eye-rotating muscles are
anchored in the outer wall of the eye (the sclera), they essentially
squeeze the eyeball, raising pressures within the large posterior
(vitreous) chamber, causing it to elongate. Experiments that planted
sensors inside he posterior chamber of the eyeball in macaques measured
elevations in pressure when the monkeys were forced to focus on nearby
objects. Although direct pressure measurements have not been made in
humans, people's eyeballs elongate very slightly when they focus on
nearby objects. It has therefore been hypothesized that growing children
whose eyeball walls have yet to fully strengthen and who stare
persistently at nearby objects stretch the eyeball's walls so much that
they permanently elongate, ever so slightly, but enough to cause myopia.
Extreme and incessant close work might also cause this process in
adults. People whose job requires them to spend long hours with their
eyes pressed into microscope lenses often suffer from progressively
worsening myopia.
The close work hypothesis is controversial and has never been tested directly in humans.
It also fails to explain the findings of other experiments on animals,
which indicate that abnormal visual input can cause myopia independent
of close work. This phenomenon was discovered by accident when a group
of researchers studying how the brain perceives visual information
noticed that monkeys whose eyelids had been stitched shut had abnormally
elongated eyeballs, as much as 21 percent longer than normal.
Intrigued, the researchers followed up with further experiments that
showed that the monkeys' myopia was not triggered by excessive close
work but instead by a lack of normal visual input (if what a monkey sees
in a lab can ever be considered normal). More recent studies that
experimentally blurred the vision of kittens and chickens confirmed that
myopia can be caused by unfocused images, which somehow disrupt normal
eyeball growth. In addition, children who spend more time inside than
outdoors are more likely to get myopia. The mechanism by which this
abnormal growth occurs is currently unknown, but these various lines of
evidence have led to the hypothesis that normal eye elongation requires a
mix of complex visual stimuli, such as varying intensities of light and
different colors rather than the drab, muted colors typical of the
inside of the house or the pages of a book.
Whatever environmental factors contribute to myopia, the problem has been around for a few millennia, albeit less frequently in the past than now.
In fact, an inability to see distant objects is used as a metaphor in
the New Testament: "But he that lacketh these things is blind, and
cannot see afar off, and hath forgotten that he was purged from his old
sins." The condition was also diagnosed by second-century doctor Galen,
who purportedly coined the term "myopia." But until eyeglasses were
invented in the Renaissance, nearsighted people had to endure their
disability without much help. Eyeglasses have since been improved and
refined through numerous innovations, including the development of
bifocals by Benjamin Franklin in 1784. Today, people with overly long
eyeballs can see distant objects just fine with the help of technology,
and it is doubtful that myopia now has any negative effects on anyone's
reproductive fitness. In this regard, eyeglasses buffer nearsighted
people from natural selection. If anything, eyeglasses have been the
focus of much cultural evolution themselves as they have become
lighter, thinner, more multipurpose, and even invisible (contact
lenses). Eyeglass styles change constantly, enticing nearsighted people
to buy new frames every few years in order to see and be seen
fashionably.
...
We
have much to learn about myopia, but two facts are clear. First, myopia
is a formerly rare evolutionary mismatch that is exacerbated by modern
environments. Second, even though we don't entirely understand which
factors cause children's eyeballs to elongate too much, we do know how
to treat the symptoms of myopia effectively with eyeglasses. Eyeglasses
are just simple lenses that bend waves of light before they hit the
eyeball, moving the point of focus back onto the retina. Eyeglasses
permit approximately one billion nearsighted people to see clearly, and
as more countries undergo economic development, this number will surely
rise. Eyeglasses like shoes, are now so ubiquitous that they have gone
from being unattractive - "men seldom make passes at girls who wear
glasses" - to being neither unnoticed or fashion accessories.
The
high prevalence of nearsightedness, combined with the way we use
eyeglasses to treat the problem's symptoms rather than its causes,
raises several hypotheses about how we promote dysevolution of this
disease. One controversial idea, based on the theory that close work
causes myopia, is that eyeglasses actually exacerbate the problem. If
contractions of the eye's muscles cause myopia in the first place, then
giving corrective glasses, which cause all distant objects to appear as
if they were close, sets up a positive feedback loop by causing
everything to appear close. As noted above, not all the evidence is
consistent with this theory, but it has received some support from a few
studies that apparently decreased the progression of myopia in children
by giving them reading glasses. An alternative idea, based on the visual deprivation hypothesis,
is that eyeglasses neither prevent nor exacerbate myopia, but they may
indirectly promote other factors that cause myopia by making it easier
for children at risk of myopia to spend too many hours reading or doing other indoor activities that provide insufficient visual stimuli. One obvious solution is to encourage these children to spend more time outside. Another might be to replace boring printed pages (such as this one) with exciting electronic books that are more visually stimulating with intense changes in color and brightness that would challenge young eyes. Wouldn't it be cool if children's books were projected brightly and dynamically on distant walls? Illuminating interior environments more brightly and colorfully might also help.
We
have much to learn about myopia, but how and why people become
nearsighted and how we help them highlights several typical
characteristics of dysevolution. First, like many evolutionary
mismatches, myopia is unwittingly transmitted by parents to their
children in a non-Darwinian manner. Although certain genes may
predispose some children to becoming nearsighted, the primary factors
that cause myopia and that parents pass on to their children are
environmental, and it is even possible that eyeglasses sometimes
exacerbate the problem. Second, we arguably know enough to try to
prevent nearsightedness from developing, but so far its prevention has
received little attention. I suspect our efforts to prevent myopia would
be much more intense if eyeglasses were less effective and less
attractive.
The Story of The Human Body: Evolution, Health, and Disease. Lieberman, p. 329-337.