Behavioral and neuronal determinants of negative reciprocity in the ultimatum game

Abstract

The rejection of unfair offers in the ultimatum game (UG) indicates negative reciprocity. The model of strong reciprocity claims that negative reciprocity reflects prosociality because the rejecting individual is sacrificing resources in order to punish unfair behavior. However, a recent study found that the rejection rate of unfair offers is linked to assertiveness (status defense model). To pursue the question what drives negative reciprocity, the present study investigated individual differences in the rejection of unfair offers along with their behavioral and neuronal determinants. We measured fairness preferences and event-related potentials (ERP) in 200 healthy participants playing a computerized version of the UG with pictures of unfair and fair proposers. Structural equation modeling (SEM) on the behavioral data corroborated both the strong reciprocity and the status defense models of human cooperation: Not only more prosocial but also more assertive individuals were more likely to show negative reciprocity by rejecting unfair offers. Experimental ERP results confirmed the feedback negativity (FN) as a neural signature of fairness processing. Multilevel SEM of brain-behavior relationships revealed that negative reciprocity was significantly associated with individual differences in FN amplitudes in response to proposers. Our results confirm stable individual differences in fairness processing at the behavioral and neuronal level.

No Robust Association between Static Markers of Testosterone and Facets of Socio-Economic Decision Making

“…Pictures of the participants who gave consent of their pictures being used in further studies were used for the analyses reported below. Eighty-six percent of the sample of Kaltwasser et al ( 2016 ) agreed and their data is reported here.…”

“…The reported data stems from a sample of 84 females and 91 males ( N = 175) who took part in a larger study investigating socio-emotional processes and abilities. Participants gave consent of their pictures being used for further investigations (Kaltwasser et al, 2016 ). The mean age of this sample was 27.62 ( SD = 5.4).…”

“…They were explained that they would receive monetary offers made by six previous participants, but the actual offers came from six pseudo-proposers (50% females). Due to the EEG methodology whose data is published elsewhere (Kaltwasser et al, 2016 ) we required an experimental protocol of the UG which allows for a specific offer distribution and high signal-to-noise ratio, e.g., many trial repetitions. Hence, it was necessary to deceive the participants in the origin of the proposals they saw.…”

“…Economists argue that negative reciprocity reflects altruistic punishment (Fehr and Gächter, 2002 ), since the rejecting individual is sacrificing own resources. However, recent studies suggest that self-interest, in terms of status defense, plays a substantial role in decisions to reject unfair offers (Yamagishi et al, 2012 ; Kaltwasser et al, 2016 ). According to the above mentioned biosocial model of status (Mazur, 1985 ), individuals with high levels of testosterone should be more likely to retaliate, e.g., have a greater desire to harm those who committed unfair acts.…”

Analysis of different sources of measurement error in determining second-to-fourth digit ratio, a potential indicator of perinatal sex hormones exposure

“…The data was collected as a part of a larger study conducted at the Humboldt University in Berlin (Kaltwasser, Hildebrandt, Wilhelm, & Sommer, 2016). There were 213 participants, 50% female, with the mean age of 27.8 years (ranging 17 to 40) of heterogeneous levels of education (24% elementary & high school, 42% students, 34% university graduates).…”