Chapter 26. Our brains intrinsically
mislead us
Our
intuition and instincts can mislead us in some important ways unless we are
alert to avoiding them.
Our brains are
very useful organs in solving problems. Merely relying on intuition to solve a problem
or make the right choice has some well-known limitations, however. Optical
illusions and magic tricks are examples familiar to all of us in which
appearances are deceiving. Consider the following picture:
The straight
line appears to be AB, but it is really AC. There are many such optical
illusions, and magic tricks often take advantage of them.
Magic tricks
and optical illusions are examples in which we know our brains are fooled by
appearances. Other ways in which we are deceived are more subtle. The following
list offers some flaws in our natural instincts, which are discussed in turn.
Behaviors that can lead us astray:
(1) The
power of association.
This point goes back to the message of the correlation chapter, that
correlation does not imply causation. Unfortunately, our minds are very easily
influenced by the associations we observe. In an experiment done by
psychologists approximately a decade ago, students were shown an item of
clothing (e.g., jacket or sweater) and told to imagine that it had been owned
and worn by someone famous or infamous. They were then asked to rank the desirability
of wearing that item. The imagined previous ownership had a powerful effect.
Items whose imagined previous owner was infamous were regarded as highly
undesirable, whereas items imagined to be from the noble or famous were
regarded as desirable. Of course, we know well that people collect items
previously owned by the rich and famous. The fact that the desirability of an
item is based on its history of previous ownership reflects just how strongly
we respond to associations.
Advertisers use
this principle effectively. Endorsements of a product by someone famous is now
routine and begets the personality high dollars (e.g., Michael Jordan endorsing
shoes, football players endorsing beer, Elizabeth Taylor endorsing her
perfumes; the movie "Attack of the Killer Tomatoes" portrayed an ad
in which Jesus Christ endorsed an electronics company). The practice works
because of the association people make between the product and the personality,
which may have nothing whatsoever to do with the quality of the product.
Another advertising strategy which makes use of this principle is to advertise
a product in an appealing setting - Coca Cola being consumed by exuberant,
happy people, cars being driven on scenic roads or featured with people in
remote settings. In the "old" days, cigarette commercials were
allowed on television, and the Salem brand was typically advertised in a
"springtime" setting with a young man and woman; Marlboro was
portrayed in a remote Western setting by a man on horseback. In neither case
did the commercial make any reference to the quality of the product. It was
just a gimmick to build an association between the product and a situation that
the viewer was likely to enjoy.
The fact that
we are respond to associations means simply that we need to be aware of this
limitation and to separate our analysis of a phenomenon from the setting in
which it is observed.
(2) Innate
responses.
Closely related to the point above is the fact that we have many built-in
behaviors. Situations that evoke fear and greed are very powerful at getting
our attention. Sex (sex appeal) is another factor generating a strong response.
Advertisers commonly use sex appeal to build an association with their product,
as per (1) above. Greed is evoked by some ads as well, but fear is used much
less, perhaps because fear is not a good emotion to associate with a product
you want to sell. However, American Express travelers checks used
the fear of vacationers being victimized by theft as a way to promote their
product. Fear and greed are also two of the main driving forces behind most
cons and scams. Most scams succeed because of greed, but once people get sucked
in, the fear of exposure (or of notification to the IRS of illegal activities)
is used to sustain the con. Many chain letters evoke both fear and greed in
offering vast rewards for sustaining the chain (i.e., for sending money) while
warning of the extraordinary bad luck that has befallen those who broke the
chain.
Ideas that evoke
these strong emotions can develop a contagious, social momentum that can have
unfortunate consequences. Michael Shermer (1997, Why people believe weird
things,
W.H. Freeman and Co., NY) describes two instances of epidemics of false
accusations: Medieval English Witch crazes (1560-1620), and much more recently,
the "recovered memory" accounts of sexual abuse by parents
(1992-1994). In the witch craze, the number of accusations arose from nothing
to hundreds over a couple decades. The recovered memory epidemic was much more
precipitous, accelerating from none to over 10,000 accusations in under 2 1/2
years. Then, as evidence to support the wild claims failed to surface, the
accusations died out. Harmless examples of these epidemics of emotion-invoking tales
nowadays are often described as "urban legends," because they evoke
such strong emotions that people spread the story rapidly and aggressively.
(One urban legend tells of a businessman who went into a hotel bar one night
and awoke the next day in a bathtub, with both his kidneys surgically removed.)
The point is that stories which evoke strong enough emotions and are told to
enough people can create a hysteria that interferes with a careful evaluation
of the evidence.
Control is
another feature that is important to us. A situation that denies a person
control over an outcome that affects them is more likely to be avoided than one
that allows control. It is well known, for example, that people are willing to
accept much higher levels of risk when they are given the choice than when not.
For example, people are much more inclined to fear flying than driving, even
though driving is much more dangerous. And people are very intolerant of low
levels of pesticide residue in food, even though many people freely accept the
risks associated with smoking and with drinking.
Built-in
responses go far beyond these few cases just mentioned. People have favorite
colors, they find certain shapes more appealing than others, and a person's
"body language" and dress has a big influence on the responses of
others. These factors can be very important when persuasion is an integral part
of the goal. Lawyers and business people in particular must heed these factors,
highlighting the simple fact that many people make decisions and choices in
non-scientific ways.
3) Wanting
to know we are right.
One of the most damaging tendencies of ours is the search for confirmation
rather than truth. If we just paid a large sum to purchase a car, we look for
ways to convince ourselves that we made a good choice. We do not want to find
out that it could have been purchased for less at another dealer, nor that some
flaw in its design has just been discovered. Instead, we want to feel that we
made the right choice.
This behavior
can spill over and affect our ability to make good choices. We typically
approach a situation with some initial preference, and we subconsciously bias
our evaluation in favor of that preference. This problem is common even among
scientists, because most scientists have strong preferences among the different
models and theories they are testing. It is extremely easy to unconsciously
bias a test by seeing only what they want to see. This human weakness motivates
the use of double-blind designs.
4) Rewriting
the past.
We all forget things, and we are aware that we can't remember some things. But
for those things of which we have a clear memory, it seems that our memory
should be trusted. Not so. Our memories of even recent events can be faulty, as
demonstrated by the different responses of people who witnessed the same recent
events. (This point was visited with experimental tests of eyewitness
identifications of people.) But as the event falls further into our past, our
memory of it becomes increasingly rebuilt. Psychologists have been very
successful recently in showing how suggestible people are, by describing wholly
fictitious "memories" to a person and then later discovering that the
person now remembers the incident as if it were true. We thus need to be
careful to document events when they happen.
5) Skip the
details.
Much of how we respond to new information depends on our "world view"
of things. Each of us has a mental model of how society, nature, and the
universe works, and each new fact or observation is either accommodated into
that view (perhaps changing it slightly) or discarded as unimportant or wrong.
As we noted in the first chapter of this book and in the class response to the
first-day questionnaire, people have very different world views about some
things (e.g., the paranormal). However, some features are common to most
people: they by-and-large prefer simple explanations of things and prefer
apparent certainty. Observations and other models with both of these features
are easier to accommodate in a world view than are those incorporating
complexity and uncertainty. Even science operates this way, because simple
models are preferred over complicated ones until the simple ones must be
rejected. Thus, people and science are more accepting of explanations that
appear simple and unambiguous.
Conclusions. This list of inherent
limitations of the human mind is certainly (!) incomplete. The simple point of
this chapter is to remind us that we each have many behaviors that interfere
with our ability to objectively and rationally evaluate evidence. We can train
ourselves to understand and avoid these pitfalls, but identifying them is the
first step. Understanding these pitfalls also enables us to understand how
other people will make mistakes in objective thinking. Con artists and
magicians are masters of exploiting these weaknesses in people, but even aside
from those extreme cases, we need to be alert to our tendencies to make poor
choices.