Sensory perception, especially vision - is a figment of your Imagination. "What you're experiencing is largely the product of what's inside your head," says psychologist Ron Rensink at the University of British Columbia in Vancouver, Canada. "It's informed by what comes in through your eyes, but it's not directly reflecting it."
Given the basic features of your visual system, it couldn't be any other way. For example, every 5 seconds or so, you blink. Yet unless you' re thinking about it, as you probably are right now, you don't
notice the blackouts because your brain edits them out.
Blinking is just the tip of the iceberg. Even when your eyes are open they're only taking in a fraction of the visual information that is available.
In the centre of your retina is a dense patch of photoreceptor cells about 1 millimetre across. This is the fovea, the visual system's sweet spot where perception of detail and colour is at its best. "When you move away from the fovea, visual acuity falls away really quickly, and colour vision disappears", says Rensink. About 10 degrees to the side of the fovea, visual acuity is only about 20 percent of the maximum.
What that means is you can only capture a tiny percentage of the
visual field in full colour and detail at any one time. Hold your
hand at arm's length and look at your thumbnail That is roughly the
area covered by the fovea. Most of the rest is captured in fuzzy
And yet vision doesn't actually feel like this: it feels like a
movie. That, in part, is because your eyes are constantly flitting
over the visual scene, fixing on one spot for a fraction of a second
then moving on. These jerky eye movements are called saccades and
they happen about 3 times a second and last up to 200 milliseconds.
With each fixation your visual system grabs a bite of high-resolution
detail which it somehow weaves together to create an illusion of
That's remarkable given that during saccades themselves, you are
effectively blind. Your eyes don't stop transmitting information
as they lurch from one fixation to the next, but for about 100
milliseconds your brain is not processing it.
Look in the mirror and deliberately flick your eyes from left to
right and back again. You won't see your eyes move - not because the
movement is too fast (other people's saccades are visible), but
because your brain isn't processing the information.
Given that you perform approximately 150,000 saccades every day, that
means your visual system is "offline" for a total of about 4 hours
during each waking day even without blinking (Trends In Cognitive
Sciences, vol 12, p 466). Yet you don't notice anything amiss.
Exactly how your brain weaves such fragmentary information into the
smooth technicolour movie that we experience as reality remains a
mystery. One leading idea is that it makes a prediction and then uses
the foveal "spotlight" to verify it. "We create something internally
and then we check, check, check," says Rensink. "Essentially we
experience the brain's best guess about what is happening now."
In conjuring up this "now", the visual system has to do something
even more remarkable: predict the future. Information striking the
fovea cannot be relayed instantaneously to conscious perception:
first it has to travel down the optic nerve and be processed by the
brain. This takes several hundred milliseconds, by which time the
world has moved on. And so the brain makes a prediction about what
the world will look like about 200 milliseconds into the future, and
that is what you see. Without this future projection you would be
unable to catch able, dodge moving objects or walk around without
crashing into things.
There's another huge hole in the visual system that can render you
oblivious to things that should be unusable. The jerky movements that
shift your fovea around the visual scene don't happen at random -
they are directed by your brain's attentional system. Sometimes you
consciously decide what to attend to, such as when you read. At other
times your attention is grabbed by a movement in your peripheral
vision or an unexpected noise.
The problem with attention is that it is a limited resource. For
reasons that remain unknown, most people are unable to keep track of
more than four or five moving objects at once. That can lead your
visual system to be oblivious to things that are staring you in the
The most famous demonstration of this "inattention blindness" is the
invisible gorilla, a video-based experiment created by Daniel Simons
and Christopher Chabris at the University of Illinois at
Urbana-Champaign. Viewers are asked to pay dose at attention to a
specific aspect of a basketball game, and around half completely fail
to see a person in a gorilla suit walk slowly across the screen, beat
their chest and walk off again.
Blind to bias
Whatever your opinion of President Barack Obama, it isn't hard to
find someone who disagrees. A recent poll in the US found that Obama
is the mast divisive president since the 1950's: 81 per cent of
fellow Democrats think he's doing a good job but only 13 per cent of
opposing Republicans agree.
How can so many people make a judgement about the same person and
come to such different conclusions? The obvious explanation is that
they are biased - by their political affiliations, by the media, by
their friends and family and much else.
This obvious explanation is correct. But who, precisely, is biased?
It depends who you ask. Those who approve of Obama think the
conservatives, and their media, are the biased ones. Those who don'
t, think it's the liberals. In fact, they are both right.
As any psychologist will tell you, pretty much everything you think
and do is coloured by biases that you are typically totally unaware
of. Rather than seeing the world as it is, you see it through a veil
of prejudice and self-serving hypocrisies.
To get a handle an this, think about your own opinion of Obama. You
probably believe your view to be an honest and objective assessment
based on a range of evidence from both sides. Perhaps you'll
grudgingly acknowledge that you feel the way you do because you are
liberal/conservative, but then reassure yourself that being liberal/
conservative is the only rational choice, so that's OK.
You have just experienced the illusion of naive realism - the
conviction that you, and perhaps you alone, perceive the world as it
really is, and that anybody who sees it differently is biased.
According to Emily Pronin, a psychologist at Princeton University, this conviction is "inescapable and deep".
If, at this point, you are thinking: "Yeah, right, that might be true
of other people, but not me," then you have fallen foul of yet
another aspect of the illusion: the bias blind spot. Most people will
happily acknowledge that such biases exist, but only in other people.
"It's not that we're blind to the concept of bias, or to the fact
that it exists," says Pronin. "We're just blind to it in our own
Why are we so blinkered? The problem is that our biases- which form
and solidify in childhood and early adulthood- operate below the
radar, in our subconscious. It is not that people do not look inwards
to question their own judgements and beliefs. Many do. But their
biases are not consciously available for inspection, so they leap to
the conclusion that their beliefs are correct and based on rational
Many of the biases are a harmless variant of the positive illusions
we routinely entertain in order to shelter our fragile egos from
reality, such as a tendency to take credit for success but deny
responsibility for failure.
Others are more serious. Few people believe that they are racist or
sexist, and their beliefs are honestly held, and yet time and again
they are betrayed by their actions. In one experiment, people were
shown a picture of a man and a woman and asked to say which they
would prefer as police chief. They were also told that the male
candidate was "streetwise" and the female candidate "formally
educated", or vice versa. Most people chose the male candidate and
then, when asked why, justified their decision by saying that
whichever quality had been attributed to him was more important for
While opinions are obviously ripe for bias, facts are also at its
mercy, with people adept at interpreting the world to fit with their
existing beliefs. For example, environmentalists interpret the fact
that most scientists and governments are convinced that humans are
changing the climate as open-and-shut evidence that we are. But
sceptics just see a conspiracy. No amount of new information will
change their minds, and yet on the whole, both camps sincerely
believe their views are unbiased and rational.
Similarly, we seek out information that fits with our beliefs and
ignore or dismiss information that doesn't. This "confirmation bias"
has been shown time and again, for example in experiments in which
people are asked to read a range of evidence about a contentious
topic such as capital punishment. Even when exposed to arguments on
both sides, most people interpret the evidence in a self-serving way,
accepting the data that supports their views and dismissing or
ignoring the rest. The scary thing is that they have no awareness of
doing it. Similarly, confronting people with new information that
contradicts their beliefs more often than not ends up hardening their
Sadly, even knowing that you are biased doesn't necessarily help. "I
know that I am susceptible to all sorts of biases because I'm a human
being," says Pronin. "But in a given instance, I'm still not likely
to be aware of it."
Head full of half-truths
I remember it like it was yesterday. It's a warm and sunny English
afternoon and I'm playing outside in the garden. Suddenly a shiny
silver aircraft appears in the clear blue sky. My mother picks me up
and points to it; neighbours come out of their houses to watch. The
aeroplane is Concorde, climbing out of Heathrow airport on one of its
I can play this memory over and over in my head as easily as watching
a YouTube clip, and yet I know it almost certainly cannot be real.
Even though Concorde could have passed over our house on test
flights, I only lived there until 1971, when I was barely out of
nappies. And Concorde was white, not silver.
Where does the mismatch between my memory and reality come from?
"We've known since the 1960s that memory isn't like a video recording
- it's reconstructive," says psychologist David Gallo of the
University of Chicago. The collection of snapshots known as
"autobiographical memory" is not a true and accurate record of your
past - it is more like a jumble of old diary entries, photographs and
newspaper clippings. "Your memory is often based on what you've seen
in a photograph or stories from parents or siblings rather than what
you can actually recall," says Kimberley Wade, a memory researcher at
the University of Warwick in the UK.
In other words, one of the most important components of your
self-identity - your autobiographical memory- is little more than an
If that sounds implausible, consider that over the past three decades
psychologists have demonstrated beyond any doubt that memory is
staggeringly fallible and suggestible.
Most of the evidence comes from false?-memory research, where
psychologists deliberately plant fake memories into people's
heads. In one famous experiment, Wade and colleagues used doctored
photographs and fake parental testimony to convince people they had
been taken on a fictitious hot air balloon ride as a child. In
another, pioneering researcher Eiizabeth Loftus, now at the
University of California, Irvine, planted memories of meeting Bugs
Bunny at Disneyiand - impossible, as Bugs is a Warner Bros character.
The success rate of such flagrant manipulation is only about 30 per
cent, but Gallo says that everybody's memory is susceptible to some
extent. "It's an automatic consequence of how our brains process
information," he says. "You cannot remember everything so your mind
summarises and remembers the gist of experiences. You form
associations and draw inferences. That gives memory great power, but
it comes at a cost."
It' s one thing to implant memories in a controlled lab setting, but
how often does it happen in real life? "We don't have a firm grasp on
that," says Gallo. "How could you really know, without some measure
of what actually happened or some corroborating evidence?" Even so,
he says the fact that memory is so easily tricked in the laboratory
suggests that it must be in daily life too.
There are a number of lines of evidence that this is the case. Some
of the best come from studying "flashbulb" memories of momentous
events such as the terrorist at tacks of 9/11 or the death of
Princess Diana. Many people have a vivid recollection of what they
were doing when they heard the news of such events, and are very
confident that these memories are accurate. But guess what: these
memories turn out to be wrong a surprising amount of the time.
Within days of 9/11, psychologists at the University of Illinois at
Chicago asked nearly 700 people where they were, what they were
doing, how they heard the news and who i hey were with at the time. A
year later they asked them again. More than half of the participants
had changed their story on at least one count? while still expressing
supreme confidence the their memories were accurate.
Flashbulb memory is also highly suggestible. In 2002, psychologists
from the University of Portsmouth in the UK went to a local shopping
centre and asked people about their memories of the death of Diana,
including whether they had seen "the footage" of the actual crash.
Nearly half said they had, despite the fact that no footage exists.
An even higher percentage of people confidently "remembered" seeing
non-existent TV footage of a Boeing 747 crashing in Amsterdam, the
Netherlands, in 1992.
If such vivid and confidently held memories can be so riddled with
inaccuracy and open to revision, it is probably true that all
autobiographical memories are suspect. "I don't think you can put a
figure on it, but I'd be confident that the vast majority are not 100
per cent accurate," says Wade.
Again, there is evidence that this is the case. When researchers at
the University of Canterbury in New Zealand asked twins about their
shared childhood, they discovered that most pairs have at least one
disputed memory - an event they are both convinced happened to them
and not to their twin. Gallo also suggests that spousal arguments,
which often revolve around disputed accounts of the same event, is an
area ripe for exploration.
It also turns out that my Concorde memory is not that unusual. Last
year, Giuliana Mazzoni at the University of Hull in the UK found that
20 per cent of people have autobiographical memories that they do not
believe to be true, often because they contradict established fact.
Does it matter that our autobiographical memories are flawed? "In
some ways it's terrifying to think just how spectacularly wrong they
might be", says Wade. "memories are part of your narrative, part of
your self? identity." There are legal ramifications too. If you
witnessed a crime and were asked to give testimony about It in court,
how confident would you be of giving an accurate report?
In many other respects, though, it matters not. My memory of seeing
Concorde has no material effect on my life. In fact, according to
Wade, the Illusory quality of memory is now seen as a strength rather
than a weakness. Memory is no longer conceived as being exclusively
about the past, but as part of a generalised "mental time travel"
module that allows us to construct and test future scenarios based on
past experience. If memory were inflexible that would not be
possible. It seems having a head full of half-truths is the price we
pay for being able to see the future.
How's your driving? If you are anything like the average person, you
probably think it is pretty good. One study found that 74 per cent of
drivers believed themselves to be better than average behind the
wheel. And, perversely, those who had been in a crash were slightly
more confident about their abilities than drivers who had not been.
This, of course, does not reflect reality. Unless there are a handful
of truly dreadful drivers, not everybody can be better than average.
And yet if you ask people to rate themselves on almost any positive
trait - competence, intelligence, honest, originality, friendliness,
reliability, and many others - most put themselves in the
better-than-average category. Ask them similar questions about
negative traits and they will rate themselves as less likely than
average to possess them.
This egotistical illusion has been dubbed the "better-than-average
effect." It is incredibly pervasive, yet goes largely unnoticed. In
an ironic twist, most people believe themselves more resistant than
than average to having an inflated opinion of themselves.
We also inflate our opinions of loved ones. Around 95 per cent of
people rate their partner as smarted, more attractive, waker and
funnier than average. And as anyone who has endured a 30-something
dinner part will testify, parents almost universally rate their
children as cleverer, cuter and more developmentally advanced than
The better-than-average effect is just one of a number of positive
illusions - ways we kid ourselves that we are special. Another is
optimism bias, as well established effect characterized by
unrealistic expectations about the future. Most people expect to live
longer and more successful lives than average while underestimating
their chances of getting divorced, falling ill or having an accident.
And the more (or less) desirable the outcome, the stronger people
believe it will (or won't) happen to them.
Where do such illusions come from? According to Jonathon Brown as the
University of Washington in Seattle, one of the originators of the
theory of positive illusions, it all starts in childhood. "Parents
create them by fawning over their children," he says.
The fawning doesn't stop there. Throughout life we have an innate
tendency to divide the world into "Us" and "them." As soon as you
forge a connection with someone, you become part o their in group -
and humans are hard wired to see members of their in group more
positively than others. In this way we all sign up to various mutual
appreciation societies that exaggerate our virtues, ignore our faults
and look down on outsiders. No wonder most of us feel excessively
positive about ourselves.
Far from being pathological, though, positive illusions are now
viewed as being a marker of a healthy mind. People who don't harbour
them are more likely to be clinically depressed - a state called
depressive realism. but however deluded you are about yourself,
chances are you are even more so about how you think others perceive
Everyone wonders and worries about how they come across to others,
and most of us think we have a pretty good handle on it. But we
don't. "People are mower near as good at it as they think, " says
Nicholas Epley, a behavioural scientist at the University of Chicago.
That is not to say was are completely useless. If you think of
yourself a generous, for example, other people probably do too. Just
not quite to the extent you might like. Form moment to moment
however, we are surprisingly poor at intuiting how we are coming
across. This is largely down to something called the "spotlight
effect" - the deluded belief that everything you do and say is being
closely observed and scrutinized. "Because we're so aware of
ourselves it can be easy to think that others are noticing us when
they're not," says Epley.
As a result, we blow everything out of proportion. "Say you spill
some water on yourself so it looks like you peed your pants," says
Epley. "You assume everyone is going to notice. But they don't,
because the world doesn't really revolve around you." People also
assume that their emotional states are broadcast to all and sundry
when in fact they are largely invisible.
It also works the other way. If you do or say something you think is
especially clever or admirable, you're likely to overestimate the
extent to which other people will notice. Most of the time they won't
even register because they are too busy tending to their own ego. The
central problem is that you know yourself to well. "You're an expert
on yourself," says Epley. That means you notice all kinds of subtle
things about yourself that others simply don't. They see general
This is compounded by the fact that we have difficulty guessing what
other people are thinking. "We have imperfect tools for getting into
their minds," says Epley. "We watch their faces and behaviour and try
to get some sense of what they're thinking, but behaviour doesn't
always reflect attitudes very well."
Surprisingly our lack of insight doesn't disappear when we're around
people we know well: accuracy does go up, but only slightly. There is
even evidence that your ability to read the mind of your spouse
actually drops after the first year of marriage. "People are actually
better at knowing how well they're communicating with a stranger. You
believe you know your partner very well as you spend more time
together, but this can actually create more of an illusion of insight
then actual insight," says Epley.
Perhaps the area where we have the least insight is physical
appearance. Everybody knows what they look like, but when it comes to
judging how we look, we're absolutely holes. For example, if you ask
people to locate a photograph of themselves in a sea of faces they
find it faster if it has been morphed to look more attractive,
suggesting we all think we're better looking than we actually are.
"When we ask people to rate how attractively they will be rated by
somebody else and correlate it with actual ratings of attractiveness,
we find no correlation," says Epley. "Zero! This still shocks me. For
crying out loud, you ought to get some sense of whether you're hot or
not. But it seems not."
Who's in control?
This is the big one. The notion that we have free will - the ability
to exercise conscious control over our actions and decisions - is
deeply embedded in human experience. But the more we learn about the
physical universe and the human brain, the less plausible it becomes.
One argument goes as follows: the universe, including the bits of it
that make up your brain, is entirely deterministic. The state it is
in right now determines the state it will be a millisecond, a month
or a million years from now. Therefore free will cannot exist.
Neuroscience has also chipped in. Around 30 years ago psychologist
Benjamin Libet discovered that if you ask people to make voluntary
movements their brains initiate the movement before they become
consciously aware of any intention to move. Other experiments have
since been performed along similar lines, leading many
neuroscientists to conclude that free will is an illusion.
But it feels so real. We all have a sense of agency - the conviction
that even though we did one thing, we could have done another, and
that at any given mount we have free choice of any number of actions.
Yet it seems that this is an elaborate illusion created by your
brain. This conclusion is inescapable. We are really deluded.
From New Scientist Magazine issue 2812.
May 16, 2011 by Graham Lawton