Social distance modulates the process of uncertain decision-making: evidence from event-related potentials

Social distance affects risk perception in uncertain decision-making, but how this effect works and the mechanism of how social distance influences the early processing stages of uncertain decision-making are still unclear. This investigation aimed to explore how social distance influences risk-taking during uncertain decision-making using the Iowa Gambling Task with recording of event-related potentials.

A total of 57 healthy subjects (36 female) participated in the modified single-choice Iowa Gambling Task when they gambled based on three quantified social distances (self, friend, and stranger). The social distance between participant and beneficiary was quantified on a scale of 0-100 points, with 0 representing self, 5 representing a close friend, and 100 representing a stranger.

Three stages of uncertain decision-making were analyzed. Behavioral results showed that social distance worked interactively with choice frame, and high social distance made people choose a more advantageous deck and a less disadvantageous deck than low social distance. The P300 in the choice-evaluation stage, which reflects stimulus discrimination, directly proved this result by showing that gambling for a stranger caused higher P300 when evaluating an advantageous deck and lower P300 when evaluating a disadvantageous deck than for others. Decision preceding negativity in the response-selection stage represents the anticipation of risky choices: this was larger with high social distance when choosing a disadvantageous deck. Feedback-related negativity and feedback-related P300 had motivational significance, showing smaller amplitudes when gambling for a stranger than for oneself.

These results provide evidence that social distance works interactively with choice frames of uncertain decision-making. People at high social distance are more risk-taking in an advantageous frame and more risk-avoid ant in a disadvantageous frame.