Says ""extroversion", in contrast to more introverted people." Extroversion describes outgoing people who enjoy meeting and making friends with people. Brian tells the audience in his TED talk that there are three natures of people and that extroverts help us understand them: “First, our biogenic nature, our neurophysiology. Secondly, our sociogenic nature or second nature, which has to do with the cultural and social aspects of our lives. And third, what makes you individually you – idiosyncratic – what I call your “idiogenic” nature. Brian describes how he finds it intriguing that extroverts always need stimulation. Brian had mentioned introverts who are people who prefer their own company and are very shy. He explains which category he falls into: “I'm an introvert, but I have a central project, which is to profess. I'm a professor. And I love my students and I love my field. And I can't wait to tell them what's new, what's exciting, what I can't wait to tell them. And so I behave in an extroverted way, because at eight in the morning students need a bit of humor, a bit of commitment to carry on during the tiring days of studying." Brian brings up the idea that people can temporarily change their personalities due to some things