Lovely. Hopefully this will help me make my PCs different from each other.
Now I want to write a giant excited monologue about how different people express the same emotion and how part of it's based on personality type and part of it's on build, and how I knew two completely identical twins (and dated one) and you would
never mistake them because one led with their mid-torso and kept their shoulders back, and one always slouched a little and led with their head, and were shockingly, incongruously different even with the same hair and clothing style. And I would suggest looking at really fantastic actors who disappear into their roles, like Gary Oldman or Tilda Swinton, and how they shift the muscles of their eyes and mouth differently depending on their character, and carry tension in different parts of their body, and how that translates into very different-looking action even if they're performing the same basic muscle mechanics.
Except that shit would just get embarrassing, so instead I'll say that I'm glad people are talking about body language.