View full lesson: http://ed.ted.com/lessons/should-you-trust-your-first-impression-peter-mende-siedlecki You can't help it; sometimes, you just get a bad feeling about someone that's hard to shake. So, what's happening in your brain when you make that critical (and often lasting) first judgment? Peter Mende-Siedlecki shares the social psychology of first impressions -- and why they may indicate that, deep down, people are basically good. Lesson by Peter Mende-Siedlecki, animation by TOGETHER.