“…Guilt aversion is an important factor of cooperation that lives up to the expectations of others, since people suffer from guilt if they disappoint others [10,11,12,13] (see Materials and Methods for a more detailed definition). Both laboratory and field experiments have supported this theory for populations in both the East and the West (e.g., East [14,15,16], West [11,17,18,19,20,21,22,23,24]).…”