New Scientist Books The Brain: A user’s guide
Making the right decision is difficult and perilous, not least because your brain has many
inbuilt biases that lead you to behave in ways that defy logic and good sense. Here’s a guide
to some of the choicest of these flaws. See how many you spot as you go about your day
(though beware, having these biases may prevent you from being able to spot them).Avoid the flaws
that lead you astray
DUNNING–KRUGER
EFFECT
The bias of illusory superiority.This is the tendency of people with
low ability to mistakenly overestimate
their competence.
The Dunning–Kruger effect is a close
cousin of the better-than-average effect –
the statistically impossible effect in which
the majority of people rate themselves
more favourably than average.
There’s also the reverse Dunning–Kruger
effect, know as Imposter Syndrome, where
a competent person feels like a fraud who
is about to be found out.ENDOWMENT EFFECT
The tendency to value things
more highly just because you
own them."Let me pick up an ashtray from a
dime-store counter, pay for it and put
it in my pocket — and it becomes a special
kind of ashtray, unlike any on earth,
because it's mine", wrote Ayn Rand in
her novel The Fountainhead.
This feeling is common, and leads us
to make irrational decisions, like refusing to
swap an item for something of higher value.
The endowment effect is one reason
why the prospective purchaser of your old
car won’t pay the price you think it’s worth.HYPERBOLIC
DISCOUNTING
A strong preference for
getting something now over
something of higher value
in the future.If you were offered £50 today or
£100 tomorrow, the latter would be
the obvious choice. It’s less clear-cut when
the delay grows. Would you still wait a
year for the £100? As the time gap grows,
so does your preference for the
immediate reward.
Hyperbolic discounting is the reason
why many people’s retirement funds are
empty. But as retirement looms, suddenly
the "future’"isn’t so far away, and hyperbolic
discounting comes back to bite.STATUS-QUO BIAS
A preference for the
current state of affairs, and
the feeling that any change
from this is a loss.This bias is linked to our desire for
familiarity, and the observation that we
feel more regret for bad outcomes
resulting from new actions than for bad
consequences that arose from inaction.
It’s one reason why you still drink Coke,
when in blind tests you actually
preferred a rival brand.BLIND-SPOT BIAS
The tendency to recognise the
impact of bias in other people’s
judgements, but failing to see
them in your own.If you suffer from this (which you
certainly do) you’re not alone. Everyone
thinks they are less biased than other
people. This effect is related to the
self-enhancement bias – the tendency to
see yourself in a positive light. This blind
spot means you won’t be able to adapt
your behaviour, even if your errors of
judgement are glaringly obvious when
carried out by other people.GAMBLER’S FALLACY
The mistaken belief that
if something has happened
more frequently than normal,
it will happen less frequently
in the future.
Also known as the Monte Carlo fallacy,
because of a famous incident at a casino
roulette wheel there in 1913. The ball
landed on black 26 times in a row and
gamblers lost millions betting against black
in the next spin. The chances were actually
50:50 but many people thought a red was
due next time. The gambler’s fallacy is the
reason why, after having four boys, you
think you’re going to have a girl next.