One interesting thing I took away from the article - most of the scientific evidence cited by Professor Sapolsky is built on fMRI analysis of reactions to faces

One interesting thing I took away from the article - most of the scientific evidence cited by Professor Sapolsky is built on fMRI analysis of reactions to faces. Given that most of our online interactions are completely text-based, what cues are we using to determine if someone is Us or Them? Do the same emotion-first impulses apply when our entire perception of another person's identity is based on the content of their written words?