## Thursday, June 7, 2007

### The devil's advocate

This is a cool experiment that I learned when I read the June edition of New Scientist. Try it and you’ll be amaze on the way how our mind functions. It is called the ‘Wason Card Selection Task’.

You are given 4 cards, ‘D’, ‘A’, ‘2’, and ‘5’ written on the front of the card. You are needed to prove this statement by just flipping only 2 cards out of the 4. The statement is:

“If there is a D on one side, there is a 5 on the other”.

So, which card will you flip?

75% of the respondents flipped D and 5. But did the statement said anything about if there is a 5 on one side, there is a D on the other? No. So, why do we need to flip the ‘5’ ? Interesting isn’t it.

To confirm this theory, the solution is actually to disprove it, so you just need to flip D and 2. The reason:
For D, if the reverse isn’t 5, the statement is false.
For 2, if the reverse isn’t D on the other side, so the statement is false

Wason concluded that in an argument, we mostly tend to use facts and numbers which only support ours and we very seldomly try to find things which weakens our arguments. This explains why when we are needed to evaluate alternatives, we end up bias towards one and we ignore the others. This is christened ‘The Ubiquitous Confirmation Bias’. This can closely associated to our way of thinking where we always consider the strength but never the weakness. Sometimes, most of the times, the best way to evaluate an issue or ourselves is trying to identify the weaknesses and improve it to the better. So, when it comes to making decisions or justifying an argument, try to ‘bang’ yourself first. Do you get what I mean? =)