Will the real extroverts please stand up?

Despite how true personality tests might feel, a lot of them are pseudoscience. But it turns out there is science behind at least one of the big personality factors: introversion versus extroversion. So what makes someone an introvert or an extrovert? And is one innately better than the other (because it turns out one is on average happier!)Guest: Sana Qadar for All in the Mind