1.1. Background and Significance
Social support has long been recognized as vital to human health and wellbeing [In addition to human social support, research has recently begun to examine the effect of animal-derived social support on stress reactivity. Historically, companion animals (i.e., pets) have been recognized as providers of instrumental social support by providing tangible services such as herding, guarding, hunting, etc. However, pets are increasingly recognized for their ability to provide emotional support, both in formal roles (e.g., as therapy animals) and as companion animals. Many pet owners in the US consider their pets members of their family [Indeed, studies have found that the presence of a friendly dog reduces self-reported and cardiovascular measures of stress reactivity during a stressful procedure compared to when alone [Existing studies examining the effect of companion animals on stress reactivity have focused on a single type of stressor. However, to our knowledge, there has not been a study directly comparing how animal-derived social support may differentially impact stress reactivity depending on the nature of the stressor (i.e., a cognitive stressor vs. a social stressor). A meta-analysis in 1999 found that human-derived social support was, overall, related to lower heart rate, systolic blood pressure (SBP), and diastolic blood pressure (DBP) reactivity but found evidence of significant moderators depending on the support provider and the type of stressor (i.e., conducting a speech versus performing arithmetic or anagrams) [