  One might quibble with some of the details.  Perhaps subjects did not believe that the easy ways of stopping the painful experience Batson provided, such as leaving the viewing room, would stop it.  (For an account of an experiment done in reply, favouring Batson, see Stich, Doris and Roedder 2010, as well as Batson 2011 135–145.) Perhaps a Batson-proof egoistic hypothesis could be offered: say that subjects believe that the only way of stopping the pain (or avoiding self-punishment) is by helping (though whether subjects have this belief might be tested for on its own).  But on the whole, Batson’s experiments are very bad news for psychological egoism.  (For further discussion of Batson, see May 2011a and Slote 2013.)