remember that because prisoner's dilemma doesn't contain -additional- terms for your empathy (it's already baked into the payoffs as they are) it's best to model the other prisoner as being an outgroup member. still think cooperation is a good idea?
personally i think you wouldnt really pull the lever. too much of a wimp to pull the lever. youd look at the lever and really hum and haw but by the time you work up the courage to pull it the trolley would be long gone. youd return home and not think of it again. imo