Why Our Brains See the World as "Us" versus "Them" from Scientific American

This one devolved into a low key religious war at my current shop, with all sorts of interesting undertones. Absolutes lurk on either extreme of the argument. Grass-is-always-greener thinking peppers the spectrum. Rational arguments include acceptance that there are appropriate use cases for either typing paradigm, and weight the tradeoffs between the two specific to a situation.