Presence of a significant other increased facial expression of pain; presence of a stranger decreased physiological arousal; verbal support, mainly from a stranger, decreased pain and arousal; intimate relationships decreased pain through touching and viewing a romantic other

Investigating the influence of social support on experimental pain and related physiological arousal: A systematic review and meta-analysis. Xianwei Che et al. Neuroscience & Biobehavioral Reviews, https://doi.org/10.1016/j.neubiorev.2018.07.005

Highlights
•    Social presence alone did not affect pain perception.
•    Presence of a significant other increased facial expression of pain.
•    Presence of a stranger decreased physiological arousal.
•    Verbal support, mainly from a stranger, decreased pain and arousal.
•    Intimate relationships decreased pain through touching and viewing a romantic other.

Abstract: Social support is demonstrated to have mixed effects on both pain and related physiological arousal. In this study, a meta-analysis was conducted to characterise these effects. A total of 2416 studies were identified in a systematic search, among which 21 were eligible for the quantitative review. The mere presence of another person was not sufficient to modulate pain perception. However, stranger presence was identified to decrease pain-related arousal (SMD = -0.31), and the presence of a significant other increased facial expression of pain (SMD = 0.21). We further found verbal support to decrease pain (SMD = -0.69) and arousal (SMD = -0.99), and we demonstrated moderate to large analgesic effects of intimate relationships through touching (SMD = -0.95) and viewing (SMD = -0.60) of a romantic partner. Finally, we presented evidence of publication bias for pain-related arousal but not for behavioural pain outcomes. Together, our findings suggest that the impact of social support on pain is context-dependent with clear communications of support and intimate relationships being of particular importance.