Observe these two lines below. Which of them is shorter.
Just throwing a glance at this picture tells us the line below is shorter. Our eyes make that impression in an instant. In fact, both those lines with fins attached are of equal length. You can take a moment to measure them if you like.
What you see above is the famous Müller-Lyer illusion. When faced with the question above, some of you might have recognized this illusion and put yourselves on guard. Therefore, you might have resisted your first impulse to say that the line below is shorter. But that input comes from your mind, and not from your eyes. Even though you have seen this illusion before, you cannot train your eyes to see the lines as having equal length. Nor can you force them through sheer will-power. With experience though, you learn to discredit your judgement of the lengths of lines when fins are involved.
The reason you’re not able to unsee this optical illusion is because its judgement is controlled by what psychologists call the automatic system. Our thinking is informed by two systems – the automatic and the controlled systems. Our first impressions are often guided by our impulsive automatic system, but the focus and the attention to perform more complex tasks is relegated to the more careful controlled system. One feature of the automatic system is that it cannot be turned off. It can be overridden – you can train yourself to discredit its judgement as people have learnt do with the Müller-Lyer illusion. But try what you may, the first impression produced by the automatic system continues to persist.
These automatic impressions that come to mind is true of a variety of situations we encounter. They inform decisions as trivial as which restaurant to go to and which dish to order, as well as more important ones such as which applicant to hire on a job application, or which supplier to collaborate with. Under most circumstances, our automatic systems make sensible decisions – just like our eyes do. But in some cases, they are prone to prejudice and systematic biases – mistakes in our judgement that we simply cannot turn off at will. And when it comes to crucial decisions such as interviewing people for a job or deciding the severity of a prisoner’s sentence, they can have far reaching consequences.
When you know that you are in situations where you can’t trust your judgement, you are better off by closing your eyes and making those decisions – such as blind auditions for orchestra performers or anonymizing resumes and profiles before screening them for your company. Those measures have repeatedly led to fairer selection outcomes.
When our eyes cannot see too well, we put on glasses. But when our eyes cannot unsee a mistake, it is better to use blinds. It is poetic that our personification of justice is a lady with her eyes blindfolded.
Inspiration: Thinking, Fast and Slow – Daniel Kahneman