'Hiding behind a small cake' in a newspaper dictator game

We conduct an Internet dictator game experiment in collaboration with the popular German Sunday paper "Welt am Sonntag", employing a wider and more representative subject pool than standard laboratory experiments. Recipients either knew or did not know the size of the cake distributed by the dictator. We find that, in case of incomplete information, some dictators 'hide behind the small cake', supporting the notion that some agents' beliefs directly enter the social utility function.