The side of intolerance will never extend you the courtesy of peaceful co-existence that you try to extend to them. If you give them a hand they'll take an arm. Give them the chance to talk and they'll take away your right to speak. You fundamentally can't make peace with someone who wants nothing more than to see you disappear.
Cutting others off excessively. It's normal when you're in a large enough group for there to be some overlap, but some people do it constantly and are only interested in hearing themselves speak. Makes being around them impossible since I often have trouble speaking up anyways.
Edit: I took instantly to mean on first meeting them, so I may have interpreted the question wrong lol
Edit2: I also should've been a bit more careful with my words, as this kind of behavior can be attributed to an anxiety response and isn't always done out of apathy. I really apologize if I offended anyone by overgeneralizing.