Everyone's got a story about how they thought a certain friend was mean the first time they met, but realized later that he or she is actually the nicest person ever.
Generally, you've only got a few seconds to make someone want to spend more time with you. Everything matters — from your last name to the smell of your sweat (gross, we know).
Below, Business Insider rounded up various scientific findings on the traits and behaviors that make people dislike you, both online and in person.