Trait mindfulness and acute stress: a test of the stress-buffering mechanism

Excessive and prolonged stress is linked to adverse physical and psychological outcomes. Social evaluative threats such as public speaking can trigger acute stress which can elicit significant physiological and psychological stress responses. Mindfulness has been proposed as a factor protecting individuals from these responses, particularly under high-stress conditions. This study tested the mindfulness stress buffering hypothesis by examining whether trait mindfulness is linked to lower stress responses and whether this buffering effect is stronger under acute social evaluative stress, aiming to replicate a previous study. Sixty-four participants completed measures of mindfulness, anxiety, and stress before being randomly assigned to a high- or low-stress condition. Participants in the high stress condition completed the Trier Social Stress Task. State stress was assessed via subjective (negative affect, anxiety) and objective (heart rate) measures. Results showed that higher trait mindfulness was linked to lower anxiety across both conditions, (p = .005, η2 = 0.12) but not to differences in negative affect (p = .884, η2 = 0.002) or heart rate (p = .227, η2 = 0.02.) Mindfulness further moderated the relationship between trait anxiety and state negative affect (b = − 0.03, p < .05) and the effect of trait stress on state negative affect (b = − 0.08, p < .001). Findings suggest trait mindfulness has a general stress-buffering effect, rather than one specific to acute social evaluative threat, providing partial support for the stress-buffering hypothesis. Given the sample and controlled laboratory setting, generalizability to broader populations should be interpreted with caution.