Granted. The world is unchanged because when all action and perception is shifted exactly the same amount in the same way, the relative effect is net zero.
Games everywhere that have character sheets get a new field if it does not already exist called empathy. A value of 1 is set to it or it increases by 1 if the field already existed. Many arguments are had about how this effects the games. No ones actual empathy changes.
Granted. A sheet of meaningless paper appears in everyone's possession. This sheet of paper lists stats that have no effect, and among them is empathy.