Crying does not alleviate acute pain perception: Evidence from an experimental study.

Background: Whereas previous studies revealed positive effects of emotional expressions such as swearing and laughing on acute pain, systematic research on the effects of crying on pain is missing. The rationale for the current study is that either a mere emotional distraction or changes in oxytocin and opioid levels represent a mechanism through which crying modulates pain, with the timing of mood changes as crucial information for distinguishing between potential mechanisms.

Methods: In two studies, we exposed participants (Study 1: n = 57; Study 2: n = 70) to a sad movie and measured their mood, and exposed them to pain induction procedures (electric shock and cold-pressor test, respectively) before and after the film. Dependent variables were pain threshold, tolerance, and intensity. In addition to baseline and one immediate post-crying mood and pain response measurement in both studies, in Study 2, we repeated these procedures 20 and 50 min later to discern between the potential role of neurobiological substances and distraction.

Results: Crying was elicited in 28 participants in Study 1 (49.1%) and 49 (70%) in Study 2. We found no systematic differences in pain and mood changes between criers and non-criers and no systematic dose-response relationship between crying and pain responses and mood. The only significant effects ran contrary to our hypotheses, showing detrimental effects of the occurrence (Study 1) and frequency of crying (both studies) on pain threshold.

Conclusions: Results do not support the idea that crying has pain-alleviating effects, either via distraction or direct biological mechanisms.

Significance: Despite previous findings on pain alleviating effects of emotional expression and the widespread idea about the generally beneficial consequences of emotional crying, research on the possible pain alleviating effects of crying is largely missing. Two quasi-experimental studies demonstrated that crying induced in laboratory conditions does not alleviate acute pain responses, suggesting that role of crying in pain interventions is doubtful. Less directly, results cast light on the role of emotional distraction from acute pain and possible crying-related neurochemical changes.