Recently my girlfriend finished reading the Harry Potter series. She read the books back to back, page after page, one after other.

Immediately after finishing the last book (Harry Potter and the Deathly Hallows,) she picked up Six of Crows. But she some how found this book a bit hard to follow in the first few pages itself.

Six if Crows is extremely well written, but as she had grown accustomed to J.K. Rowling’s writing style, Leigh Bardugo’s style felt different and not very relatable.

Six if Crows is set in a different world (although it involves its fair share of magic and wizardry), and it can’t be called in any way a children’s book. It is fast paced, and there’s constant changing of points of views and plot twists throughout - nothing like Harry Potter. These only added to the difference felt while reading them.

Something similar happens when you get into the shower and try to bring the temperature of the water to optimum. Lukewarm water would feel hot or cold, depending on whether you hand touching it was previously in hot or cold water.

Both the above incidents are examples of The Contrast Effect.

The contrast effect is a common misconception. My friend bought a car recently. He almost ordered leather seats for his brand new car right before he called me to confirm in the last minute.

To him, $350 leather seats seemed next to nothing compared to the $35,000 price tag on the car. I told him that all industries that offer upgrade options exploit our bias due to the contrast effect. He was wise enough to listen, and later on got the same quality of leather seats for half the price from an auto shop in his neighbourhood.

I might have had saved him in this case, but later on I found out the he had been bitten by the contrast effect bug previously. He is a kind of a person who would walk an extra ten minutes to save $10 on food. But this time he took a cab for the same distance when he went to buy his $35,000 car. It’s a harmless albeit an irrational move because ten minutes is ten minutes, and $10 is $10. Logically, he should have walked this extra 10 minutes while going to buy his car as well.

Contrast effect makes an average man of 5′ 10″ look short in front of a man of 6′ 7″. So short that you will assume that he is shorter than average. Your brain uses comparisons to place things and people in context. Sometimes, this will heavily effect the outcomes.

While checking answer sheets, if teachers come across a particularly bad or good answer sheet, the next sheet they mark is usually a victim of contrast effect. That is, if a paper is particularly good, it impacts their perception of the next paper, perhaps making it look worse than it really is. Who knows, maybe you weren’t such a bad student at school.

But the reverse also happens. When marking a particularly bad paper, the next one seems so much better by comparison, and it’s highly likely that the next student gets better grade than s/he deserves.

If you are a teacher, or in some way related to grading answer sheets, needless to say, it would be a good practice to go back to the papers and recalibrate the grades to ensure that you were really comparing apples to apples.

In commerce, without the contrast effect, the discount business would be completely untenable. A product that has been reduced from $100 to $70 seems a better value than a product that has always cost $70.

Ideally, the starting price in any case should play no role. Next time if you think something like, “This share is of great value because it’s 50% below it’s peak price,” think again. A share price is never low or high. It is what it is, and the only thing that should matter to you is whether it goes up or down from that point. Train your System 2 to figure this out naturally.

We judge something to be beautiful, expensive, or large if we have something ugly, cheap, or small in front of us. We have difficulty with absolute judgments.

Contrast effect is why busy Mondays feel extra awful after a free and relaxing Sunday.

This is why you are more likely to get depressed after returning from a vacation, than not going for a vacation at all.

Contrast effect prevents you from accepting good suits, because in your head you are still comparing all of them with your long lost ex.

Final advice: we are bombarded by advertisements featuring perfect bodied supermodels through out the day. This makes us more likely to perceive beautiful people in real life as only moderately attractive. So, if you are seeking a partner in bars and pubs, try not going out in the company of your model friends. People will find you less attractive than you really are. Go alone or, better yet, take two ugly friends.