So in Aliens, I have read that James Cameron introduced the incredibly-badass , butchy-woman space marine Vasquez so that Ripley would, in addition to her relationship with Newt, come across as comparatively feminine.
What other characters seem to have a main purpose of “pegging the spectrum” - setting up an outlier example so that the lead appears more relate-able?
I thought of Niles on Frasier, but really the fact that they are so alike seems to be more about establishing that there is a world where this type of arrogant/dilettante mindset is considered okay…
Big Bang Theory: The presence and characters of Howard, Raj, and especially Sheldon end up making Leonard look almost normal in comparison. On most other shows Leonard would be the uber-geeky weird outlier.
I was going to say “the gangsters in Boondock Saints”, but they’re also the antagonists.
But I think the foils in the Boondock Saints movies still work, because they’re all like
Wow! Revenge is FUN and COOL! And the Saints are like “no, we’re doing this because we have to, but we still have fun in other ways” But they’re still vigilantes and so would look grim and weird if not for a foil character.