How resource sharing resists scarcity: the role of cognitive empathy and its neurobiological mechanisms

Abstract

Resource scarcity challenges individuals' willingness to share limited resources with other people. Still, lots of field studies and laboratory experiments have shown that sharing behaviors do not disappear under scarcity. Rather, some individuals are willing to share their scarce resources with others in a similar way as when the resource is abundant, which is crucial for the maintenance and development of human society. Here, we designed a novel paradigm in which subjects decided whether (and how much) to share an amount of "relieving resources" for counteracting unpleasant noises, which mimics real-life situations that people cost their own resources to help others escape from adversity. Overall, the robustness of resource sharing under scarcity was positively correlated with individual level of the cognitive component of empathy across two independent experiments. Resource insufficiency modulated the activations of several brain regions (including the TPJ, mPFC, and PCC) as well as the functional connection (from the rTPJ to the mPFC) within the mentalizing brain network, but the modulatory effect decreased as a function of cognitive empathy. We also applied the administration of oxytocin and found significant effects on sharing behavior among individuals with a higher level of cognitive empathy, but not their low-level counterparts. These findings highlight the importance of empathy to resource sharing under scarcity and explain the underlying neurobiological mechanisms.

Keywords: empathy; functional magnetic resonance imaging; oxytocin; resource scarcity; resource sharing.

Fig. 1

Experimental design and behavioral results of experiment 1. a) Structure of an example trial; b) results of the sharing rate for each level of resource sufficiency; c) correlations between the changing rate and cognitive component of empathy score; n.s.: not significant. ^*: P < 0.05. ^**: P < 0.01.

Fig. 2

Brain-imaging results of experiment 1. a) Brain activation of (2 × sufficient condition − [insufficient condition + highly insufficient condition]); b) brain activation of (sufficient condition − insufficient condition) overlapped with the contrast of (2 × sufficient condition − [insufficient condition + highly insufficient condition]); c) brain activation of (sufficient condition − highly insufficient condition) overlapped with the contrast of (2 × sufficient condition − [insufficient condition + highly insufficient condition]); d) visual representation of the connections between nodes for DCM analysis.

Fig. 3

Results of DCM of experiment 1. a) Model structures of the best model (green solid line with arrow indicates where the modulatory effect tool place; green arrow indicates the input; xp: exceedance probability); b) correlations between the difference between sufficient and insufficient conditions in modulation strength of the rTPJ → mPFC and cognitive component of empathy scores.

Fig. 4

Results of experiment 2. a) Effects of oxytocin and cognitive empathy score on the sharing rate; b) effects of oxytocin and cognitive empathy score on the changing rate. Each box indicates the mean value of each group. n.s.: not significant. ^*: P < 0.05.