As with oxytocin, there are genes involved in the cortisol response that when they have these small errors, or SNPs, can predispose a person to a heightened or prolonged stress response. This can be a significant reason to why the same experience that one person brushes off can lead to serious consequences in another – including anxiety, depression, PTSD, and even many chronic health issues thought to be purely physical – heart disease, obesity, autoimmune disease, and cancer just to name a few.
So when dog owner says they feel better around their dog, we now know why. One can venture that a key reason behind the healing power of dogs is the combination of increasing the oxytocin response and reducing the cortisol-driven stress response. It’s science, it’s biology, and it’s their unconditional love that makes this partnership between dogs and humans so enduring.
(1) Nagasawa, M et al Oxytocin-gaze positive loop and the coevolution of human-dog bonds. Science 17 April 2015: Vol. 348 no. 6232
(2) Petersson M et al. Oxytocin and Cortisol Levels in Dog Owners and Their Dogs Are Associated with Behavioral Patterns: An Exploratory Study