The study found that those who were more reserved were more likely to rank "Pat" as a poor housemate because the email's spelling and grammar weren't up to scratch - while extroverts were less likely to care about spelling errors.

So what does that have to do with arousal? Well, according to famed psychologist Hans Eysenck, introverts have a higher rate of arousal.

As a quote by the BBC explains: "Eysenck's theory was that extroverts have just a slightly lower basic rate of arousal. The effect is that they need to work a little harder to get themselves up to the level others find normal and pleasant without doing anything. Hence the need for company, seeking out novel experiences and risks.

"Conversely, highly introverted individuals find themselves overstimulated by things others might find merely pleasantly exciting or engaging. Hence they seek out quiet conversations about important topics, solitary pursuits and predictable environments."

Can't stand this sentence? Study finds being pedantic about grammar says a lot about our sex lives