Journal of Behavioral Medicine, Vol. 28, No. 3, June 2005 ( C  2005) DOI: 10.1007/s10865-005-4663-0 Gender and Communal Trait Differences in the Relations Among Social Behaviour, Affect Arousal, and Cardiac Autonomic Control Bianca D’Antono, 1,2,3,5 D. S. Moskowitz, 4 Christopher Miners, 4 and Jennifer Archambault 4 Received for publication: September 20, 2004 To examine the relation between social behaviour and vagal activity, the communal behaviour of healthy college men (N = 33) and women (N = 33) was manipulated while monitoring heart rate (HR) and respiratory sinus arrhythmia (RSA). The subjects were classified as low or high on communal trait. Communal behaviour was manipulated by having the subjects behave in an agreeable or quarrelsome manner in scripted role-plays. HR, RSA and self-report arousal were obtained during or immediately following baseline, experimental and relaxation periods. 2 (Gender) × 2 (Communal Trait; low/high) × 2 (Condition; agreeable/quarrelsome) ANCOVAs were performed. Men had lower RSA values when behaving in a quarrelsome fashion than agreeable and lower RSA values than women in the quarrelsome condition. In the latter condition, low communal men reported more arousal than other groups. Strong but opposite associations between RSA and affect arousal were observed in low communal men and woman. Men, especially more quarrelsome (less communal) men exhibited weaker vagal control during arousing social situations. KEY WORDS: RSA; cardiovascular reactivity; affect arousal; communion; gender differences. INTRODUCTION Coronary artery disease (CAD) is the leading cause of death in men and women in industrial societies (Scheit, 1996; Shepherd, 1998). However, the onset of CAD in women usually occurs 10– 20 years later than in men. While cardio-protection 1 Montreal Heart Institute, 5000 Belanger Street East, Montreal, Quebec, Canada. 2 Department of Psychiatry, University of Montreal, P.O. Box 6128, Succursale Centre-Ville, Montreal, Quebec, Canada H3C 3J7. 3 Department of Psychology, University of Quebec in Montreal, P.O. Box 8888, Succursale Centre-Ville, Montreal, Quebec, Canada H3C 3P8. 4 Department of Psychology, McGill University, 1205 Docteur Penfield Ave., Montreal, Quebec, Canada H3A 1B1. 5 To whom correspondence should be addressed at Department of Psychosomatic Medicine, Psychosomatic Medicine, Montreal Heart Institute, 5000 Belanger Street East, Montreal, Quebec, Canada H1T 1C8; e-mail: bianca.d’antono@internet.uqam.ca by estrogen is believed to play a role in this sex/age differential, other mechanisms may also be involved. Sex-related differences in hostility and/or in cardio- vascular reactivity (CVR) to interpersonal stress may be two such determinants of sex-related differences in CAD among younger individuals. Examination of these differences could provide insights into the possible behavioural and biological mechanisms involved in the incidence and pathophysiology of CAD in men and women. Hostility and Coronary Artery Disease Evidence accumulated over the past decades suggest a role for hostility (Barefoot et al., 1983, 1994; Haynes et al., 1980; Helmers et al., 1993; Matthews, 1982; Shekelle et al., 1983; Smith, 1992; Williams, 1987; Williams et al., 1989) in the incidence of CAD. For example, a recent prospective study of Danish men and women found that hostility was associated 267 0160-7715/05/0600-0267/0 C  2005 Springer Science+Business Media, Inc.