There is ongoing debate about whether people will be more risk-taking when they make decisions for the group under ambiguous situations (Social Interaction). As information technology enable us to get advises from others much more easily nowadays (Cultural Neuroscience), understanding the pattern and mechanism of people's risk-taking behavior change in group-decision is important for us to make more rational decisions.
The researchers (1) employed computerized Balloon Analogue Risk Task (BART) to quantify participants' risk-taking behavior. In this task, participants were asked to collect wager of current balloon or inflate it, which may explode and all wager would be lost (Brain Stimulation). In individual decision condition, participant perform the typical BART alone, while in group decision condition, two participants would sit side by side in front of the monitor and make decisions for the same balloon alternately (Behavioral Research Lab). Most importantly, they measured their event-related potential (ERP) EEG to look closely into the underlying mechanism of feedback processing. Specifically, in line with previous studies, two components were identified: the feedback-related negativity (FRN) component, which reflect rapid feedback evaluation, and P300 component, which reflects a later, attention-sensitive, more elaborate appraisal of outcome. Moreover, the Five-Factor personality traits were also collected to reflect participants' social character. Combing these methods enabled us to examine different feedback processing procedures separately, provide a new comprehensive way to understand people's risk-taking behavior in group.
Thirty healthy male students (mean 21.3 years) participated in this study.
The pump times of wining balloon (participants decide to collect the wager and stop pumping) were used as participant's risk-taking behavior measurement. Results showed that, overall, participants performed similarly in group decision condition and in individual decision condition (paired t-test: p=0.731). However, when participants were divided into two groups according to each of their five personality traits, analysis showed that participants with higher agreeableness pump the Balloon more times in group decision condition, comparing to their own performance in individual decision (p<0.030). This result was confirmed by the significant correlation between agreeableness and pump times increase (Fig. D, r=0.401, p<0.029). This increase of risk-taking behavior was not significant in participants with lower agreeableness (p=0.607), or any other personality groups (separated by median).
When comparing ERP amplitudes between different conditions, the FRN and P300 were extracted from the difference-average waveform of lost balloon and wining balloon (Fig. A). Following analysis showed that FRN were similar across these two conditions (Fig. B, p=0.519), while P300 significantly decreased in group decision condition (Fig. B, p<0.001). Most interestingly, robust correlation was found between Agreeableness and P300 decrease (Fig. E, r=0.555, p<0.001).
First, agreeableness was found to be the only measurement which were significantly correlated with the increase of participants' risk-taking behavior in group decision (Motivation, Emotion & Craving), which suggested that many cognitive processing were involved in this task and could hardly be determined by either one.Second, unchanged FRN amplitude suggest that the lower level of feedback processing did not change, as FRN reflects the early rapid evaluation of the affective or motivational impact of outcome events.Third, P300 significantly decreases in group decision and higher Agreeableness showed significantly more P300 decrease, suggest that subject with high Agreeableness perceive the negative feedback quite differently in group decision, they might be less moved by the negative feedback affectionally or attentionally. This result is not surprising considering that agreeableness is one of the five major dimensions of personality structure and reflected individual differences in cooperation and social harmony.
(1) Fang Wang, Xin Wang, Yu Pan, Hengyi Rao. (2019). Individual Agreeableness Modulates Group Member Risk Taking Behavior and Brain Activity:An ERP Study
(2) Bang, D.(2017), 'Making better decisions in groups', Royal Society Open Science, vol.4, no.8, pp.170-193
(3) Bell, S. T.(2007), 'Deep-level composition variables as predictors of team performance: A meta-analysis', Journal of Applied Psychology, vol.92, no.3, pp.595–615
(4) Bjørnebekk, A.(2013). 'Neuronal correlates of the five factor model (FFM) of human personality: Multimodal imaging in a large healthy sample; NeuroImage, vol.65, pp.194–208
(5) Bradley, B. H. (2013). 'Team Players and Collective Performance: How Agreeableness Affects Team Performance Over Time' Small Group Research, vol.44, no.6, pp.680–711