"In a famous study, spouses were asked, 'How large was your personal contribution to keeping the place tidy, in percentages? bias is not necessarily self-serving: spouses also overestimated their contributions to causing quarrels" (Kahneman, 2011, p.). Use the material in this chapter to explain why the percentages given by the two spouses would add up to more than ... As expected, the self-assessed contributions [from the two spouses] added up to more than 100%... The 100%.