The Pitfalls of Familiarity
Linda is a 31-year old single woman. She is outspoken and very bright. She majored in philosophy, and as a student, she was deeply concerned with discrimination and social justice issues. She never missed an opportunity to participate in anti-nuclear energy demonstrations.
Which one of these statements is more probable?
- Linda is a bank teller
- Linda is a bank teller and is active in the feminist movement
If you answered 2, congratulations, you’re in the majority (~85%)!
Except that it’s the wrong answer. Assume that the probability of Linda being a bank teller P(A) is 0.5, and the probability of her being active in the feminist movement P(B) is 0.8. To know the probability of those two events happening together P(C), we would need to multiply P(A) and P(B):
P(C) = P(A) × P(B) = 0.8 × 0.5 = 0.4
As we can see, P(C) (0.4) is actually lower lower than both P(A) and P(B). So, the probability of Event 2 is lower than the probability of Event 1. We could even take this to the extreme, say both events have a probability of 0.99. The product of 0.99×0.99 is 0.9801, still lower than 0.99.
The above question is known as the Linda Problem, first devised by Amos Tversky and Daniel Kahneman in the 1980s to demonstrate the conjunction fallacy.
Defined formally, the conjunction fallacy is a cognitive bias wherein one judges the combination of two or more events be more probable than any one of them happening alone despite the probability of the former is lower than the latter.
The conjunction fallacy is one of the many fallacies stemming from our sense of familiarity. In the Linda problem, most people answer wrongly because Option 2 seems more ‘representative’ of Linda. This representativeness is due to us comparing the description of Linda to a prototype or a stereotype that we already have in mind, something that we are already familiar with.
Let’s look at another example.
Answer as fast as possible. A bat and a baseball cost $1.1 in total. The bat costs $1 more than the ball. How much does a baseball cost?
If you answer $0.1, congratulations again, you’re in the majority!
At this point you must at least be suspicious that it’s not the answer, and you’re right, it’s not. The answer is $0.05, and the price of the bat is $1.05.
But hearing or reading ‘$1.1’ and ‘$1’ tricks our mind into spewing out ‘$0.1’ since $1.1-$1 = $0.1.
This perfectly demonstrates the concept of two thinking systems popularised again by Daniel Kahneman.
Kahneman postulated that we have two thinking systems: System 1 and System 2. System 1 is fast, instinctive, and reactive; whereas System 2 is more logical and deliberative. System 1 is the go-to guy in a lot of everyday familiar situations: calculating 2+2, judging whether an object is bigger than another, walking on an empty road. System 2, on the other hand, is more infrequently employed: calculating 17×24 (it’s 408, by the way), parking a car into a tight space, count the number of the letter A in a text.
Unfortunately, we often consult System 1 when we actually should consult System 2.
So as I hope you can see, just because something feels familiar doesn’t mean that it’s right. It sounds so obvious when it’s written in front of your eyes. But in practice, it’s not that easy to realise that you’re acting out of familiarity alone.
Often, when we’re asked why we do something in a particular way, we just answer along the lines of ‘that is how it has been done since forever and that is what I’m most familiar with,’ and you don’t see any problems about it. It just works, despite not being the best way to do it. And by this time the inertia is just too high for you to even consider other options or even realise that there are other options.
Going for something familiar instead of something better can easily hinder progress without even us knowing it.
One trick to avoid this is to introduce complete strangers into the scene.
In his seminal book ‘Blink’, Malcolm Gladwell tells a story of a study in which two people are asked to judge a student’s Big Five personalities by just observing their dorm room. Of the two observers, one is a total stranger to the student, while the other is their close friend.
To everybody’s surprise, strangers did better at predicting the students’ personalities than their friends on 3 out of 5 of the Big Five. The two personalities they fail to predict well were extroversion and agreeableness — two metrics that can’t really be estimated without actually interacting with the person.
When we already know someone quite well, we tend to make subjective judgments, instead of objective ones. The boundary between what they actually are, what we believe them to be, and what we want them to be becomes more and more blurry as the relationship progresses. It gets harder and harder to be objective.
I think this is also the case with many other things in life, not just people and relationships. Perspectives from new, even unexperienced people, are always much needed; especially when something has gone on for a long time without anyone ever questioning it because they have been too familiar to it to ever realise that there is something wrong. Fresh perspectives are needed to unearth some deep-seated mistakes.
Instead of gathering opinions from people who have been doing the same thing for all their life, ask what the new guy thinks. Instead of asking the wife of an aspiring politican if he is fit to be the next governor, ask a totally-unrelated college student.
Instead of accepting to do something in a particular way just because that’s how it’s been done for 10 years and that is what’s familiar to do, question the reason why it’s the case and how you can improve it.
I was fortunate enough to witness this phenomenon in the wild. Someone at work asked my friends and I, ‘At what temperature does water evaporate?’
You guessed it, most answered 100°C. Except it’s the wrong answer. If water only evaporates at 100°C, you would have to put your wet clothes in an oven. But you don’t, because water can evaporate at temperatures lower than 100°C.¹
This reminded me of Kahneman’s theory and led me to writing this piece.
References
Kahneman, D., Tversky, A. and Slovic, P., 1982. Judgments of and by representativeness.
Kahneman, D., 2011. Thinking, fast and slow. macmillan.
Gladwell, M., 2006. Blink: The power of thinking without thinking.
¹The driving force of evaporation is difference in concentration. As long as the surrounding environment hasn’t reached its saturated water concentration, water can evaporate due to the difference in water concentration. The concentration of water in your wet clothes is definitely higher than that in the surrounding air, and thus water can evaporate from your clothes at lower than 100°C.
Yes, an increase in temperature increase the saturated water concentration of a system, and that’s why heating a system induces evaporation. But evaporation doesn’t have to happen at the boiling point of a liquid. It also helps to replace air with a high water concentration (that is, humid) with air with a lower water concentration (that is, dry). This is why moving air also induce evaporation.
Evaporation requires energy input, and when our body is hot, we evaporate some sweat to deplete the heat. This is why it feels very horrible to be in a hot and humid place, since our body has difficulty to evaporate some water to cool down. This is also why we feel cold getting out of shower, even though we’ve just taken a hot shower, since the water concentration on our skin is higher than the surrounding and evaporation happens, taking heat from our body,
I can’t believe I’ve just written three additional paragraphs explaining this.
