It is often assumed extroverts do best in life, but according to a new best-selling book, introverts are just as high achievers. It claims there is a bias towards extroverts in Western society. So do we discriminate against introverts?
Barack Obama, JK Rowling and Steve Wozniak.
They might not immediately stand out as introverts, but according to Susan Cain, American author of Quiet: The Power of Introverts In a World That Can't Stop Talking, they are.
That is because she says, contrary to popular opinion, introverts are not necessarily shy or anti-social, they just prefer environments that are not over-stimulating and get their energy from quiet time and reflection.
Conversely, extroverts need to be around other people to recharge their batteries.
Cain argues that although a third of the population are introverts, most institutions, from schools to workplaces, are geared towards extroverts, while introverts are often undervalued or misunderstood.
"Whether it is job adverts using words such as 'upbeat, people person and team players', practices like open-plan offices or brainstorming, the overall ability to put yourself out there is the great value of the age.
"But research shows there is no correlation between the most talkative person in the room and the best ideas," she says.
The self-identified introvert says there is a similar pattern in schools, where speaking up in class, group work and "show and tells" is emphasised.
She also cites studies which suggest that the majority of teachers think the ideal student is an extrovert, and more extroverts are groomed for leadership positions in the workplace.
Her book, which hopes to rehabilitate the introvert, has struck a chord with readers and sparked a debate among commentators and armchair psychologists, while herTED talk has been watched by 1.5 million viewers.
Meanwhile the Guardian'sJon Ronsonis bemused that after concluding his whole family are ambiverts - which Cain defines as a mixture of extrovert and introvert - the group barely gets a mention in the book.
One introvert who can relate to Cain's campaign is Mark Dykeman, an IT business analyst from Canada. The 42-year-old, who has written a number ofblogs on introversion, agrees there are plus points to being an introvert, but says it can be difficult.
"At university there was a lot of encouragement and pressure to socialise with other people. I was OK with that for short periods of time, but after a certain point it became very tiring.
"It wasn't until I was in the workforce and I had training that I started to understand the difference between introverts and extroverts. It opened my eyes to how I'd been thinking about certain situations, and gave me a bit of comfort," he says.
Dykeman says he found it difficult to voice an opinion in meetings earlier on in his career, but soon realised he needed to speak up and make points.
"I learnt how to act like an extrovert. I think a lot of people learn the rules of the game learn to function.
"It can be a bit harder, but everyone can contribute. I'd suggest anyone that does feel uncomfortable in public settings educates themselves on introversion," he says.
Felicity Lee, a chartered occupational psychologist, says it is perfectly possible for introverts to try to act like an extrovert, but it will be more tiring for them.
American and Canadian culture tends to value the qualities of extroverts more than other cultures, but Lee thinks a bias towards extroversion also exists in the workplace and wider society in Britain.
But she says just because someone is an extrovert, it does not necessarily mean they do extroversion well.
"Someone can be an extrovert or an introvert and very self-aware and socially skilled. Or they can be very unaware. Extroversion has nothing to do with emotional intelligence, or competence," she says.
Lee also points out that there is evidence to suggest that whatever the psychological nuances, most people just want to be an extrovert.
"In the 1990s, when the Myers-Briggs personality type test went through validation with UK and Europe distributors, 92% of people said it was better to be extrovert, even though only half of the population is extrovert in the type version," she says.
Anecdotally, when you go back to the school playground, children would probably say it is better to be an extrovert - to be social and have friends, she adds.
Jo Silvester, a professor of organisational psychology at Cass Business School, says it is easy to see why such desirability exists.
She says most organisations looking to recruit would steer towards extroverts, on the assumption that they make better leaders.
But Silvester says some industries do not necessarily attract the types of personalities people might think.
"Politicians for example are a lot more introverted. In politics it doesn't pay to show all of your cards too quickly, and introverts are more willing to stand back and listen and take extra time to come up with a conclusion.
"People would probably assume sales requires extroversion, because they deal with a lot of people all of the time. But if somebody is selling to research chemists, they might need to be more introverted, as people tend to get on best with people like themselves," she says.
However, Richard Dodd, at the British Retail Consortium, says the notion of dividing people up into extroverts and introverts is over-simplistic as there are many more variables in people's characters.
He thinks people naturally tend to gravitate towards jobs that suit their personal qualities and make the best use of their abilities.
But he says most successful teams and workplaces have a mixture of individuals with a range of characteristics and qualities.
"There is a place for selling yourself and making sure your achievements are recognised in most jobs, which might be easier for some personality types than others," he says.
"But I think in successful organisations the approach to management and appraisal is to be able to get beyond the superficial impression, and to make sure people's contributions are identified and recognised - regardless of whether people are shouting from the rooftops."