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What is False-Consensus Effect?

What is false consensus effect?

What is False-Consensus Effect? And the myth of Like-Mindedness

Which do you prefer: music from the 1960s or music from the 1980s?

How do you think the general public would answer this question?

Most people tend to extrapolate their preferences on to others. If they love the 1960s, they will automatically assume that the majority of their peers do, too. The same goes for 1980s aficionados. We frequently overestimate unanimity with others, believing that everyone else thinks and feels exactly like we do. This fallacy is called the false-consensus effect. 

An experiment

Stanford psychologist Lee Ross hit upon this in 1977. He fashioned a sandwich board emblazoned with the slogan ‘Eat at Joe’s’ and asked randomly selected students to wear it around campus for thirty minutes. They also had to estimate how many other students would put themselves forward for the task.

Those who declared themselves willing to wear the sign assumed that the majority (62%) would also agree to it. On the other hand, those who politely refused believed that most people (67%) would find it too stupid to undertake.

In both cases, the students imagined themselves to be in the popular majority.

A few examples

The false-consensus effect thrives in interest groups and political factions that consistently overrate the popularity of their causes. An obvious example is global warming. However critical you consider the issue to be, you probably believe that the majority of people share your opinion. Similarly, if politicians are confident of election, it’s not just blind optimism: they cannot help overestimating their popularity.

Artists are even worse off. In 99% of new projects, they expect to achieve more success than ever before.

Of course, the business world is equally prone to such false conclusions. Just because an R&D department is convinced of its product’s appeal doesn’t mean consumers will think the same way. Companies with tech people in charge are especially affected. Inventors fall in love with their products’ sophisticated features and mistakenly believe that these will bowl customers over, too.

The false-consensus effect is fascinating for yet another reason

If people do not share our opinions, we categorise them as ‘abnormal’. Ross’s experiment also corroborated this: the students who wore the sandwich board considered those who refused to be stuck up and humourless, whereas the other camp saw the sign-wearers as idiots and attention seekers.

Perhaps you remember the fallacy of social proof, the notion that an idea is better the more people believe in it.

Is the false-consensus effect identical to Social Proof?

No. Social proof is an evolutionary survival strategy. Following the crowd has saved our butts more often in the past 100,000 years than striking out on our own.

With the false-consensus effect, no outside influences are involved. Despite this, it still has a social function, which is why evolution didn’t eliminate it. Our brain is not built to recognise the truth; instead its goal is to leave behind as many offspring as possible. Whoever seemed courageous and convincing (thanks to the false-consensus effect) created a positive impression, attracted a disproportionate amount of resources, and thus increased their chances of passing on their genes to future generations. Doubters were less sexy.

In conclusion

Assume that your worldview is not borne by the public. More than that: do not assume that those who think differently are idiots. Before you distrust them, question your own assumptions. 

Falsification of History – YOU WERE RIGHT ALL ALONG

Similar Biases:
Not-Invented-Here Syndrome – WHY YOU CAN’T BEAT HOME-MADE


The above article is from the book The Art of Thinking Clearly by Rolf Dobelli. The article is only for educational and informative purposes to explain and understand cognitive biases. It is a great book, definitely worth a read!