What is the story about?
A hug may seem like a small gesture, but the science behind it is far from minor. Each year on 12 February, Hug Day is observed during Valentine’s Week. The act itself is simple — wrapping one’s arms around another person — yet it is widely seen as a sign of reassurance, closeness and support. Beyond its emotional significance, researchers have also examined what hugging may be doing inside the body, particularly in relation to stress.
How hugs may affect stress systems
Earlier laboratory studies have suggested that affectionate touch, including hugs, may help regulate the body’s stress response. The system most often examined is the hypothalamic–pituitary–adrenal (HPA) axis, which controls the release of cortisol, a hormone closely linked to stress.
One measure researchers use is the cortisol awakening response (CAR) — the rise in cortisol levels that occurs shortly after waking. CAR tends to vary depending on stress levels and social experiences.
A recent study expanded this research beyond laboratory settings. Using daily tracking methods and saliva samples, researchers explored links between hugging and CAR in everyday life. The participants were 104 first-year university students.
What the study found
Students recorded their daily social interactions and noted whether those interactions included hugs. Saliva samples were then used to measure cortisol levels the following morning.
On days when participants reported a greater proportion of social interactions that involved hugs, their cortisol awakening response the next morning was lower than on days when fewer hugs were reported.
The sample consisted of students living on campus, mostly aged 18 or 19. Many were first-generation university students, and a substantial proportion identified as Mexican American or from other Latine backgrounds. Researchers noted that this added diversity compared with many earlier laboratory-based studies.
Limits and what comes next
The findings indicate an association, not proof of cause and effect. The study focused on young adults, and researchers said future work should include a wider range of age groups.
They also pointed out that affectionate touch can take many forms — not just hugs — and that the meaning of a hug may differ depending on who gives it.
Even so, the overall pattern aligns with earlier research: greater affectionate touch is linked to lower activity in stress-related biological systems.
How hugs may affect stress systems
Earlier laboratory studies have suggested that affectionate touch, including hugs, may help regulate the body’s stress response. The system most often examined is the hypothalamic–pituitary–adrenal (HPA) axis, which controls the release of cortisol, a hormone closely linked to stress.
One measure researchers use is the cortisol awakening response (CAR) — the rise in cortisol levels that occurs shortly after waking. CAR tends to vary depending on stress levels and social experiences.
A recent study expanded this research beyond laboratory settings. Using daily tracking methods and saliva samples, researchers explored links between hugging and CAR in everyday life. The participants were 104 first-year university students.
What the study found
Students recorded their daily social interactions and noted whether those interactions included hugs. Saliva samples were then used to measure cortisol levels the following morning.
On days when participants reported a greater proportion of social interactions that involved hugs, their cortisol awakening response the next morning was lower than on days when fewer hugs were reported.
The sample consisted of students living on campus, mostly aged 18 or 19. Many were first-generation university students, and a substantial proportion identified as Mexican American or from other Latine backgrounds. Researchers noted that this added diversity compared with many earlier laboratory-based studies.
Limits and what comes next
The findings indicate an association, not proof of cause and effect. The study focused on young adults, and researchers said future work should include a wider range of age groups.
They also pointed out that affectionate touch can take many forms — not just hugs — and that the meaning of a hug may differ depending on who gives it.
Even so, the overall pattern aligns with earlier research: greater affectionate touch is linked to lower activity in stress-related biological systems.
