Acute Stress Makes Women's Group Decisions More Rational: A Functional Near-Infrared Spectroscopy (fNIRS)-Based Hyperscanning Study

With the rapid social changes and quickened pace of life, stress may pose a severe test on collective decision-making. The present study examines how acute stress affects women's group decision-making in the context of face-to-face interaction. We adopted a functional near-infrared spectroscopy (fNIRS)-based hyperscanning technique to measure coherent neural activities in dyads engaging in an Iowa Gambling Task (IGT) under acute stress. Behavioral results showed that stressed dyads got a higher net score than dyads in control groups during late decision-making rounds, indicating more rational group decision-making performance under acute stress. The fNIRS results further manifested that greater inter-brain synchronization (IBS) was detected in stressed dyads. During the late decision-making phase, increased IBS at the frontopolar cortex (FPC) and left temporal-parietal junction (TPJ) were observed across the dyads under acute stress. The IBS at TPJ of stressed dyads covaried with self-reported cooperativeness and more rational decision-making performance of the stressed dyads. Our findings aligned with the "tend and befriend" response mode hypothesis, indicating that female dyads exhibited better decision-making performance under acute stress, and this rationality might be attributed to the enhanced cooperativeness and intensifying cooperativeness and increased brain-to-brain coupling at TPJ in stressed dyads.