Read “A Mistake” by Akhil Sharma in The New Yorker.  After the last sentence (of a 30 minute read), take a test on generalized empathy for strangers, neighbors, co-ethnics, misanthropes, bullies and snarks.  You’ll be more empathetic than your “self that did not read.”  Now the interesting part: how long until the effect wears off?  I would guess about 3-4 minutes after returning to normal activities (brushing teeth, scooping cat litter, hopefully not at the same time…).