Effect of Human Attachment Style on Horse Behaviour and Physiology during Equine-Assisted Activities–A Pilot Study

SIMPLE SUMMARY: Human–horse interaction, such as attachment and bonding behavior, is particularly important during repeated equine-assisted activities (EAA). This bond needs to be reliable, positive, and reciprocal to create a secure human–horse attachment and achieve improvements in EAA participants. This study aims to determine the effect of the attachment style (AS) of at-risk adolescents on the physiology and behavior of therapy horses during a 10-week EAA. Adolescents completed a questionnaire to determine their AS before starting the program. Horse response during the EAA was recorded, looking at horse heart rate and behaviour (the occurrence of affiliative and avoidance behaviours). Adolescents’ AS affected horse affiliative behaviour during grooming, and horse heart rate and avoidance behaviour during riding. The results indicate that horse welfare was not threatened during the EAA with at-risk adolescents. Over time, therapy horses showed overall more affiliative behaviour and less variability in their stress response (heart rate and avoidance behaviours) toward insecure AS adolescents during grooming and riding, respectively. These results suggest that insecure AS can positively impact horse response during EAA relative to secure AS in humans. However, the implications of human AS on the functioning of horse–human interaction and its mechanisms are yet unknown. ABSTRACT: Equine-assisted activities (EAA) for human well-being and health rely on human–horse interactions for therapeutic effect. At-risk participants with mental and emotional difficulties can show poor social skills and functioning relationships, potentially leading to unsuccessful human–horse interaction in EAA. This study addresses the effect of the attachment style (AS) of at-risk adolescents on horse physiology and behaviour during an equine-facilitated learning (EFL) program. Thirty-three adolescents participated in a 10-week EFL program with nine therapy horses (the same therapy horse per adolescent throughout the program). Adolescent AS was categorized into secure (n = 7), preoccupied (n = 11), dismissing (n = 1), or fearful (n = 12) using an Experiences in Close Relationships – Relationship Structure questionnaire. Horse heart rate (HR) and behaviour (affiliative and avoidance behaviours) in response to adolescents were recorded during grooming and riding. Over time, horses with fearful AS adolescents showed consistently more affiliative behaviours compared to those with preoccupied AS adolescents during grooming, and more constant HR and avoidance behaviours compared to those with secure AS adolescents during riding. These results suggest that a more predictable and less stressful physiological and behavioural response of therapy horses toward participants in EAA with emotional and behavioural difficulties can be mediated by a human insecure attachment style.