Introverts’ nervous systems react more intensely than extroverts’ to social situations as well as to sensory experiences. Extroverts’ nervous systems don’t react as much, which means that they crave stimulation, such as brighter lights and louder sounds, to feel alive. When they’re not getting enough stimulation, they may start to feel bored and antsy. They naturally prefer a more gregarious, or chatty, style of socializing. They need to be around people, and they thrive on the energy of crowds.