Hugging on its own is not an anti-stress shield, but in one of the best available studies it has been a clear marker of social support. Among 404 healthy adults, those who were hugged more on high-conflict days showed a smaller rise in infection risk after exposure to the common cold virus. This finding shows an association, not a cause, and the effect size is modest.
Researchers led by Cohen published a study in 2015 in the journal Psychological Science that followed 404 healthy adults. Perceived social support was measured with a questionnaire. Daily conflicts and the number of hugs each person had received were recorded over 14 consecutive nights via telephone interviews. After that, all participants were exposed to a virus that causes the common cold and remained under observation in quarantine.
Perceived support prevented the rise in infection risk; a risk that usually increases with more conflict. Hugging had a similar effect and accounted for 32 percent of this protective effect of support. The meaning of this number is clear: most of the effect of support is still explained by something else, and hugging accounts for only a portion of it. Among those who actually became infected, more support and more hugs were associated with milder symptoms of illness.
A warm hug in everyday life can be part of the fabric of support in a relationship — Image: AI-generated / Gemini 3.1 Flash via OpenRouter
[Further research needed: this study did not randomly assign hugging to participants. Someone who is hugged often usually also has closer relationships, and with the available data it is not possible to separate the effect of hugging from the effect of the relationship itself.]
Hugging and blood pressure: what role does oxytocin play?
The study by Light and colleagues in 2005 in the journal Biological Psychology was conducted on 59 premenopausal women. Women who reported more frequent hugs from their partner had higher baseline oxytocin, lower blood pressure and a lower heart rate. Oxytocin is a hormone that plays a role in social bonding, and in this study it explained only part of the relationship between hugging and blood pressure, not all of it.
The study by Grewen and colleagues in 2005 in the journal Psychosomatic Medicine reached a consistent result. In it, 38 couples aged 20 to 49 experienced 10 minutes of warm contact with their partner. Greater support from the partner was associated with higher oxytocin in both women and men, and in women with lower systolic blood pressure after this contact.
These two studies measure association, not the effect of an intervention. It cannot be concluded from them that ten minutes of hugging keeps blood pressure down. What can be said is this: in these samples, warm contact and partner support have been associated with calmer biological markers.
Is hugging the cause or a sign of a good relationship?
Two explanations are both still alive. The first explanation is that hugging itself is part of the pathway of the effect of support. The second explanation is that hugging is a sign of a relationship that was already reducing stress. The available data do not separate these two, because hugging was not randomly determined and people with different support networks have been compared with one another.
The effect size must also be read modestly. In the study by Cohen and colleagues, hugging explained 32 percent of the protective effect of support, and the remaining portion belongs to perceived support and other factors. A hug is part of the fabric of a relationship, not an independent intervention with a guaranteed effect.
In my clinical experience, which is not statistical evidence, clients who report warm physical contact in their relationship often also speak of reduced tension, but the severity of their underlying problem does not necessarily change. This very gap shows the boundary between personal experience and controlled evidence.
My position is clear: correlational findings should not be turned into therapeutic recommendations or into an advertising campaign for physical contact, nor should they be ignored. Their proper place is in the list of factors that measure health within the context of a relationship.
What did Freud say about affection and physical contact?
In a 1912 paper titled “On the Universal Tendency to Debasement in the Sphere of Love” (Standard Edition, volume 11), Freud distinguishes two currents in romantic life: the affectionate current and the sensual current. In his view, the affectionate current comes from the period of childhood care and attachment, and the sensual current joins it later. When these two meet in a relationship, love can contain both affection and desire. When they remain far apart, physical contact takes on a split meaning.
This framework explains why a hug does not have one meaning for everyone. For one person it can be a sign of safety, and for another it can carry a load of desire or conflict. This is a psychoanalytic reading, not empirical evidence for the physiological effect of hugging, and it does not take the place of controlled designs.
The conclusion is this: hugging is not an independent shield against stress, but in several studies it has been associated with social support and a calmer bodily response. This association is worth pursuing, because it shows that warm contact and social support can work together within a relationship. The condition is that no therapeutic promise be made of it and that future randomized studies be awaited.
It has not been proven. In the study of 404 people, hugging explained 32 percent of the protective effect of support against increased infection risk, but the design was observational and does not show causality.
How many times a day is hugging necessary?
There is no reliable number. In the common cold study, the frequency of hugs was recorded over 14 nights, but none of these three studies has determined the appropriate amount.
Does hugging friends and acquaintances have the same effect?
It cannot be concluded from these three papers. The blood pressure studies were conducted on spouses and partners, and they contain no data about hugging in other relationships.
What if someone does not like being hugged?
Forcing physical contact makes no sense. In the common cold study, perceived support itself also had a protective effect, so hugging is not the only way to convey support.
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Cohen S, Janicki-Deverts D, Turner RB, et al. Does hugging provide stress-buffering social support? Psychol Sci. 2015;26(2):135-147. PMID 25526910
Light KC, Grewen KM, Amico JA. More frequent partner hugs and higher oxytocin levels are linked to lower blood pressure and heart rate in premenopausal women. Biol Psychol. 2005;69(1):5-21. PMID 15740822
Grewen KM, Girdler SS, Amico J, et al. Effects of partner support on resting oxytocin, cortisol, norepinephrine, and blood pressure before and after warm partner contact. Psychosom Med. 2005;67(4):531-538. PMID 16046364
Freud S. On the universal tendency to debasement in the sphere of love (1912). Standard Edition, vol. 11.
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Image: AI-generated / Gemini 3.1 Flash via OpenRouter
