A self-affirmation movement centred on introverted personality is causing gentle ripples throughout popular psychology. Susan Cain, author of a best-selling book on introversion, has dubbed this movement the “quiet revolution”.

This is the story of an underdog having its day: Western society tends to devalue and marginalise introverts, but introverts can be a proud people, with strengths that are seldom appreciated. Now, with the help of advocates like Susan Cain, many are standing up to say so (quietly).

It’s a compelling tale, but what does psychological science have to say about introverts?

What does it mean to be an introvert?

Decades of research has shown that personality is organised in terms of five broad traits:

Conscientiousness: industriousness, orderliness, dependability Agreeableness: politeness, compassion, kindness Neuroticism: anxiety, moodiness, irritability Openness to experience: curiosity, imaginativeness, insightfulness, and Extraversion: boldness, talkativeness, outgoingness

Everyone’s personality can be described in terms of where they lie on each of these five dimensions. In this scheme, an introvert is simply the opposite of an extravert, so they’re a person who is relatively quiet, reserved and shy. If you tend to keep in the background, let others drive the conversation, etc, chances are you’re an introvert.

In pop culture, however, introversion means much more than quietness. In her book, Susan Cain describes introverts as:

Reflective, cerebral, bookish, unassuming, sensitive, thoughtful, serious, contemplative, subtle, introspective, inner-directed, gentle, calm, modest, solitude-seeking, shy, risk-averse, [and] thick-skinned.

When describing herself, Cain lists her introverted qualities as “thinking before I speak, disliking conflict, and concentrating easily”, as well as having “a strong inner life”.

Through the lens of personality science, it’s difficult to see how many of these descriptions relate to the extraversion-introversion continuum, or indeed to one another. In addition to introversion (unassuming, calm, solitude-seeking, shy), there are traces of conscientiousness (concentration, deliberation), agreeableness (modest, gentle, disliking conflict) and openness to experience (reflective, cerebral, bookish, thoughtful, serious, contemplative, introspective).

This is because the popular conception of introversion is really a blend of several distinct personality traits.

Apples and oranges?

Much of this is old news. Popular writers are aware of the scientific definition of introversion and tend to explicitly contrast it with their own. On the other hand, academics are aware of the popular definition and tend to pointedly ignore it.

For what it is worth, the popular usage more accurately captures both Carl Jung’s original conceptualisation of introversion as well as its literal meaning (from the latin intro, meaning “inward”, and vertere, meaning “to turn”).

But the reason psychological science has shifted away from this conceptualisation is that it conflates multiple, distinct traits. Characteristics such as shyness, deliberation, modesty and bookishness simply do not “go together”, in that the presence of one typically correlates with the presence of the others. This means that the trait introduced in Cain’s book as “The North and South of Temperament” does not exist.

Self-described introverts might reasonably retort: “so what?” Must one’s sense of identity line up with a major axis of human individuality? Certainly not. Indeed, it would be underwhelming if our personality boiled down to a single trait.

But if the quiet revolution values self-knowledge as well as self-affirmation, then it matters that being quiet, shy and solitude-seeking does not entail the various other characteristics that are widely ascribed to introverts.

It was recently shown that popular notions of introversion can be broken down into four distinct traits. This recognises, for instance, that not all introverts are contemplative and introspective; being quiet on the outside actually says nothing about your “inner life”.

Of course, it is probably no coincidence that exactly four flavours of introversion were identified in this research: this is exactly what you would expect given five fundamental dimensions of personality. That is, introverts can vary in terms of their levels of conscientiousness, their agreeableness, and so on.

Convenient half-truths

The popular view of introversion can seem a little self-aggrandising: it takes low extraversion and then bolts on many desirable bits of other personality traits. By combining introversion with elements of conscientiousness, for instance, Cain is able to list persistence and concentration among the key “powers” of introverts.

This also helps to minimise the downsides of being introverted. A case in point is the evidence that extraverts are generally happier than introverts, which holds up in many cultures.

Popular writing on introversion tends to brush this literature aside. This is easy to do if your vision of introversion smuggles in elements of conscientiousness, agreeableness, and openness to experience, all of which are linked with greater happiness.

The revolution, reinterpreted

Interestingly, the patchwork of traits commonly called introversion might be the key to the success of the “quiet revolution”. After all, if this was just a story about quiet and shy people feeling undervalued, we’d probably never hear about it.

Mounting a revolution takes hard work, persistence, and determination. These elements of conscientiousness feature in many personal reflections on life as an introvert.

The quiet revolution would also have benefited from openness to experience: Cain and other quiet revolutionaries are thoughtful, curious people. They have thought deeply about who they are, and what they have to offer the world.

Viewed from this perspective, the quiet revolution is not really about introversion. Rather, it serves to highlight the broad range of other human strengths that often go unnoticed in quiet people.