I used to own a Maruti Alto and few years back while it was in the basement parking of my flat, there was a adventurous rat who got inside the my hood with something to eat. There is a hole that rat ventured into and unfortunately it got stuck and met its end.
The rat started to decompose in some time and there was strong smell in the car. I searched all over my car but couldn’t find one. I took it to a car washing place nearby and the guy there started to smell with his nose like a detector and with increasing intensity near the passenger side front door he narrowed down to the exact place. God had gifted him amazing smelling sense. They took out the gasket to reach to a hole where the harness was running and started putting a jet of water. Whatever remained of the rat did come out and smell went down considerably.
During that time I bought a car freshener and was using it quite a bit. Idea was to counter the smell of the rat.
Fast forward to May 2018, I had changed my car and had given it for servicing. While removing things for servicing I found the same car freshener that I used during that time. There was still some left and just for finishing it off I sprayed in my car. As I was driving the car after the smell of the fragrance was hardwired in my brain with the rat smell. My mind was telling me that this is nothing but a dead rat in the car again. I was almost sure that again there is rat dead my car.
In the current science of human behavior Daniel Kahneman and Amos Tversky had proposed System 1/System 2 model. Here it can be seen that system 1 could associate the smell of the fragrance directly to the rat smell and came to conclusion that it is due a rat which had again decomposed in my car. I was not convinced with that completely and System 2 kicked in. I went to office that day and asked couple of my colleagues to witness the smell. When I asked them if there was a smell of dead rat which can be easily identified but they gave a negative answer. Then I asked them if they smelled some fragrance in the car and they sounded positive about it. Only then my System 2 came to the reality that system 1 was fooling around with me.
There may be huge number of way our biases will be coming into our ways to getting the right decisions in our life. We should be aware of such biases that exists in humans and try to overcome this blindness whenever possible.