Asymmetric Dominance Effect: How To Make Sense of Human Irrationality - An illustration showing three wine bottles labelled 'A', 'B', and 'C' from left to right. Wine bottle 'A' has a price tag of $5, while wine bottle 'B' has a price tag of $10. Wine bottle 'C' has a price tag of $90. Wine bottle 'C' is also explicitly marked as "Decoy"

The asymmetric dominance effect is an empirical phenomenon that helps us make sense of many of the irrational decisions that human beings make. What’s more, it also explains how nature works in general with respect to decisions. In this sense, this phenomenon extends beyond just intelligent life forms.

One could benefit from the knowledge of the asymmetric dominance effect when making important life decisions. So, it comes as no surprise that one of the fields that is closely associated with this effect is decision theory.

In this essay, I will be illustrating how the asymmetric dominance effect works using practical and intuitive examples. Following this, we will look at some of the challenges this effect poses to us and how we may overcome them. Without any further ado, let us begin.

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The Dating Experiment

It is safe to say that when it comes to human decisions, choosing dating partners ranks as one of the more important ones. Let me tell you the story of the asymmetric dominance effect in dating.

A bunch of students set out on an initial task of choosing between two hypothetical persons. They considered both of them as prospective dating partners. The rule was simple: they had to choose one of the two.

To help make their decision, the conductors (of the experiment) offered the students the following information about their prospective dates:

Option 1: Adam — in the 81st percentile of attractiveness, 51st percentile of dependability, and 65th percentile of intelligence.

Option 2: Bill — in the 61st percentile of attractiveness, 51st percentile of dependability, and 87th percentile of intelligence.

If you look at this information objectively, each student had three criteria to base their decision on (if you ignore the names of the options). Both Adam and Bill are comparable in dependability. However, they trade blows when it comes to attractiveness and intelligence.

Asymmetric Dominance Effect: How To Make Sense of Human Irrationality — An illustration showing two stick figures — Adam on the left and Bill on the right. Adam says, “I am attractive”, while Bill says “I am intelligent”. Who would you choose?
Adam Vs. Bill — Illustrative art created by the author

Rather expectedly, the students were divided in their choices. The result was 50–50. Again, this is not far from real-life decision-making. Some people are interested in beauty, whereas some are more into intellect. But it is what happened next that makes this experiment interesting.

The Asymmetric Dominance Effect in Dating

Next, the conductors (of the experiment) introduced a third option:

Option 3: Chris — in the 81st percentile of attractiveness, 51st percentile of dependability, and 54th percentile of intelligence.

Again, if you ignore the names, Chris is comparable to Adam in terms of attractiveness and dependability. It is just that he ranks lower in intelligence as compared to Adam. So, in essence, he is an irrelevant alternative, since Adam ranks superior in intellect.

One would guess that the students would still be divided between Adam and Bill, with Chris securing a minority of the votes (Chris can be considered a dumbed-down version of Adam). But this is not what happened.

This time, almost two-thirds of the students chose Adam. Isn’t that interesting? But why? Well, it turns out that by comparing Adam with an inferior version of Adam (Chris), the students’ perceived value of Adam increased.

But doesn’t this conflict with what they thought previously? Well, yes. This experiment reveals two important points:

1. Human beings are not perfectly rational.

2. The introduction of a carefully chosen irrelevant alternative can deterministically affect the rational behaviour of a group of individuals.

The people who conducted this experiment were psychologists Constantine Sedikides, Dan Ariely, and Nils Olsen. You might think that this is a psychological phenomenon. Well, as it turns out, that is also not true.

The Asymmetric Dominance Effect Beyond Humans

Scientific researchers Tanya Latty and Madeleine Beekman from the University of Sydney conducted experiments with the slime mold Physarum polycephalu, which is a single-celled organism for most of its life. But under conducive conditions, these little creatures band up to form a collective being known as a plasmodium.

The plasmodium makes decentralised decisions akin to a democratic framework to search for food. The researchers established that the mold likes oats (food) and hates light. Using these input conditions, the team offered the mold two options on a Petri dish:

Option 1: 3 grams of oats placed in the dark.

Option 2: 5 grams of oats placed in the light.

The plasmodium chose 50–50 on average. But later on, the research team introduced an irrelevant alternative in the form of a 1 gram oats pile placed in the dark.

This tipped the scales, and this time around, the plasmodium went for the 3 grams pile placed in the dark more than thrice as often as the 5 grams of oats pile placed in the light.

Curiously, other researchers have established similar irrational-seeming behaviour in other species of animals as well.

What are the Disadvantages of the Asymmetric Dominance Effect?

In a brilliant exposition, mathematician Jordon Ellenberg explained how in a famous US election, the presence of an underdog candidate enabled the publicly unfavoured candidate to actually win the election.

In other words, even though the majority did not want the candidate to win, the person won! “How could that possibly be true?”, you ask? Well, that is the very nature of the asymmetric dominance effect.

It comes as no surprise when I say that individual human behaviour is not perfectly rational. We see it all the time when we make seemingly-stupid decisions on a daily basis. It is just that we tend to make more rational decisions collectively as a group.

This means that we are more rational as a group on average. But on certain occasions, even groups tend to be on the irrational side. With a carefully chosen irrelevant alternative, this just becomes strangely deterministic.

Asymmetric Dominance Effect: How To Make Sense of Human Irrationality — An illustration showing three wine bottles labelled ‘A’, ‘B’, and ‘C’ from left to right. Wine bottle ‘A’ has a price tag of $5, while wine bottle ‘B’ has a price tag of $10. Wine bottle ‘C’ has a price tag of $90. Wine bottle ‘C’ is also explicitly marked as “Decoy”
The Decoy (asymmetric dominance effect) — Illustrative art created by the author

This phenomenon is often used by marketing/advertising folks to drive specific consumer behaviour. In marketing, this effect goes by the name of the decoy effect.

So, with all these disadvantages and implications of the asymmetric dominance effect laid out, what can we do to avoid falling for the trap?

How to Avoid the Asymmetric Dominance Effect

One of the primary intuitions that misleads us in the context of this effect is binary decision making. If we stop treating decisions as binary outcomes, we can deflect many of the disadvantages of the asymmetric dominance effect.

Take the dating experiment story for instance. Instead of choosing one out of the three candidates, say that the students assigned a ranking of preference of the three candidates and we assigned weight-factors to each choice based on the various ranking lists.

Then, the collective weight-factor sum (of the whole group) would eliminate the irrational-seeming behaviour. While this seems like black magic, the fundamentals of this process lie in mathematics.

The method that I just outlined was developed by a French mathematician named Jean-Charles de Borda in the field of ballistics. The respective weight-factor sum for each candidate is technically known as the Borda Count.

The solution, then, is not only a technical one, but is also a mathematical one. Since I intend this essay for the common man, I am skipping the mathematical details of this approach. But should you be interested in it, do let me know in the comments section, and I will cover it in a future essay.

But for now, I will conclude this essay with the following question: Who would have thought that mathematics (of all things) would explain/solve challenges of human irrationality?

Reference and Credit: Jordon Ellenberg, Sedikides, Ariely, and Olsen, Latty and Beekman, and Jean-Charles de Borda.

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