Early life stress and deprivation are known to have lasting biological and behavioral consequences across species. In this study, Awalt et al. (2024) investigated how adverse early experiences influence epigenetic regulation, stress physiology, and attachment behaviors in domestic dogs, a species that shares many social-cognitive traits with humans.
The researchers examined 47 owner–dog pairs, including dogs rescued from abusive or neglectful environments and matched controls. They focused on methylation patterns of two genes: the glucocorticoid receptor gene (NR3C1), associated with stress regulation via the HPA axis, and the oxytocin receptor gene (OXTR), linked to social bonding and attachment. Dogs also participated in an attachment paradigm that included separation events to assess cortisol levels and attachment styles.
Results showed that dogs with adverse life histories exhibited distinct NR3C1 methylation patterns that varied with age, and lower OXTR methylation compared to control dogs. Although cortisol responses did not differ significantly between groups, the magnitude of cortisol changes was linked to NR3C1 methylation, suggesting an epigenetic influence on stress regulation. Importantly, dogs with adverse pasts were more likely to display insecure attachment styles, and higher OXTR methylation was associated with increased odds of insecure attachment.
These findings demonstrate that early adversity can leave lasting molecular and behavioral marks on dogs, influencing both their stress physiology and their emotional bonds with humans. This highlights the importance of supportive environments in mitigating the long-term impacts of early trauma in companion animals.
Source: Awalt, S. L., Boghean, L., Klinkebiel, D., & Strasser, R. (2024). A dog’s life: Early life histories influence methylation of glucocorticoid (NR3C1) and oxytocin (OXTR) receptor genes, cortisol levels, and attachment styles. Developmental Psychobiology, 66(3), e22482. Published March 14, 2024.
