Exaggerated envy and guilt measured by economic games in Japanese women with anorexia nervosa

Masanori Isobe,Tomomi Noda,Toshiya Murai,Shun’Ichi Noma,Michiko Kawabata,Ryosaku Kawada,Noriko Matsukawa,Teruhisa Uwatoko,Ema Murao,Hidehiko Takahashi

doi:10.1186/s13030-018-0138-8

Abstract

BackgroundAnorexia nervosa (AN) patients are assumed to express high levels of guilt and envy. Ultimatum game (UG) is a standard behavioral task that focuses on interpersonal behavior when splitting a sum of money between two players. UG studies consistently demonstrate that people tend to decrease their inequity in outcomes, one explanation being that economically irrational decision-making may partly arise from the emotions guilt and envy. We assumed that AN patients would perform excessively fair in UG, reflecting high guilt and envy.MethodsWe utilized UG to investigate the characteristics of guilt and envy among 24 Japanese AN patients and 22 age-matched healthy controls (HC). The relation between the outcome of UG and decision strategy confirmed by post-experimental questionnaires was analyzed.ResultsAs proposer, AN offered a larger amount to the responder compared with HC (p = 0.002) while, on the other hand, as responder, AN demanded much higher allocation to accept the offer compared with HC (p = 0.026). Regarding the strategy as responder, AN put more emphasis on fairness and less emphasis on monetary reward compared with HC (p = 0.046, p = 0.042, respectively).ConclusionsThe results indicate that Japanese AN patients demonstrate strong preference for fairness, with high guilt and high envy. High sensitivity to guilt and envy of AN patients can affect not only their own behavior concerning eating attitude and body shape, but also decision-making in interpersonal situations. Behavioral experimental settings among social situations will enable us to evaluate and help actual decision-making in the real life of patients.

Highlights

Anorexia nervosa (AN) is characterized by distorted body image and excessive dieting [1]
Ultimatum game (UG), focusing on interpersonal behavior when splitting a sum of money between two players, is one of the most widely used tasks, as guilt and envy are addressed with this task [12]
Demographics There was no significant difference in IQ between the healthy controls (HC) and AN groups (Table 1)

Summary

Introduction

Anorexia nervosa (AN) is characterized by distorted body image and excessive dieting [1]. Individuals with AN feel guilt for “indulgent” eating or loss of control in an eating setting [2], and they feel envy when they see someone very slim [3] In this manner, those with AN are assumed to express high levels of guilt and envy [4, 5]. Adolescents with AN showed more increased guilt than healthy To understand these emotions, economics games, which can assess decision-making in social situations [8] and provide a quantitative value to examining the psychopathology by predicting optimal adaptation to a changing environment [9], have been used in psychiatric populations [10, 11]. We assumed that AN patients would perform excessively fair in UG, reflecting high guilt and envy

Results

Discussion

Conclusion