I’ve been reading a book called Thinking: Fast and Slow by
Dr Daniel Kahneman who is a Psychologist and won the Nobel Prize in Economics
in 2002. His findings challenge the assumption that human rationality prevails
in economic judgement.
In the book he writes at length of the two systems we use
when making judgements or coming to conclusions. Simply put ‘System 1’ is our subconscious
intuitive self that knows what is going on immediately and allows us to make
very quick judgements. These can be judgements like the path of a ball through
the air, or for an experienced driver, the minor change in lane position of a
lorry you are driving past on the motorway that could mean the driver is not
fully attentive on the road. The moment you register the movement you ‘know’
where the ball is headed or to give the lorry a little more space. System 2, in
contrast, is our rational self the bit we think of as our internal monolog and
the one that does the hard work to solve a difficult problem in a rational way.
It’s not quite as simple as that but this explanation will suffice for this
post.
Normally our System 2 receives the immediate answer from
System 1 and simply rubber stamps it before moving on, but having said that if
something is fully thought through our System 2 normally ‘wins’ over System 1
and we accept our System 2 judgement.
To put this into practice take a look at the picture below
for a moment and ask yourself what is going on:
You immediately notice that this little chap is scared, you
then see that he is all dressed up in his brand new school uniform and your
System 1 serves up the narrative that he is worried about his first day at
school, and you probably feel sorry for him and hope that it worked out ok in
the end.
I’ve no idea if this is the right story because the picture
was taken by ‘Andre2203’ and shared on a CC BY-SA 4.0 licence, but it’s the one
we all jump to and it feels right to us. That’s our System 1 serving up a
narrative to our System 2, which runs with it without modification. For all we
know he might love school having been for the last 6 months and is actually scared
of a big dog just out of shot.
Then there’s System 2, which is typified by answering the
following calculation:
24 x 17 =
Our System 1 gives up on this immediately and hands it over
to System 2 for analysis. We have all done quite a lot of maths in the past and
our System 1 has some experience of this type of problem and can tell us that
the answer is more than one or two hundred, but if 528 was suggested it couldn’t
confirm or deny if that is the right answer. So, go on, try solving this question
without a calculator and feel System 2 working. You may notice that 24 is
almost 25 and that 25 x 17 is an easier place to start before taking the 17 off
at the end. You can do 25 x 10 pretty easily so that just leaves the 25 x 7
left. And so on, and so on. Your short term memory quickly fills up with
intermediate answers while trying to calculate the next part of the sum. It’s
hard work, you probably looked away from the screen into space and your pupils
will have dilated while you thought about it. At some point you will have
either given up or found an answer and you pupils will have returned to their
previous size. If you have not yet worked it out, the answer is 406.
So, let’s try an easier maths question where you will find
the answer coming to mind effortlessly. The question goes like this:
A bat and a ball cost
$1.10.
The bat costs $1 more
than the ball.
How much does the
ball cost?
The answer to this question came quickly and easily, System
1 is apparently good at this type of maths. But unfortunately you got the
answer wrong. The answer you got was 10 cents, but if the ball cost 10c then
the bat must cost $1.10 giving a total price of $1.20. So in fact the answer is
not 10c, but 5c and now you know the answer provided by System 2 your System 1
is forced to agree.
I’ve tried this question on a few folks at work who are
degree qualified professional engineers, and they, like me, all got it wrong the
first time as well so don’t beat yourself up too much. This is a sort of
mathematical illusion and works a bit like an optical illusion. But we should
be aware that we can make this type of error and never be afraid of working
something out long form. Don’t take the first answer you came up with for
granted.
While we are here I’ll also point out that 24 x 17 is not
406 as I asserted above, it’s actually 408. If you spotted that error then well
done, keep up the good work.
So to conclude, I hope that this has demonstrated that you
and I have limits to our rationality. Even for something with a definite answer
we often assume to ourselves that the first thing that comes to mind is the
only answer and must be the right one and then don’t check for other
alternatives. To think better we need to be aware of this ‘Jumping to conclusions bias’.
We also need to remember that even though we’ve thought it
through carefully we still might not know the answer. We don’t actually know
why the little boy in the picture looked scared so we don’t need to jump to a
conclusion as to what is going on. It is acceptable to be ‘agnostic’ on that
issue, and seek for better evidence like searching out and asking 'Andre2203' before concluding.
It’s also good to know that when pressed our System 2 can overrule
the judgement our System 1 made; we can be more rational when we want to.
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