Hugging and Kissing Studies!
About a dozen studies have been done on the medical and psychological effects of hugging and/or kissing.
In the 1980s, Germans studied kissing, together with insurance company records. Married men were studied and separated by whether or not they kissed their wives each day before going to work or not. Those who kiss their wives before work were found to live on average 5 years longer. They earn 20-30% more and they have fewer car accidents.
The book The How of Happiness reports on a study in which students were divided into two groups, one of which was the control group. The other group was instructed to hug as many people as reasonable or possible each day, with a minimum recommended number of 5 separate persons hugged at least once per day (rather than simply hugging a girlfriend 5 times). Moreover, the hugs were instructed to be full-frontal hugs, using both arms of those hugging or at least the one hugging.
A number of the male students found it a serious challenge to hug more than a few people a day, but they perservered and tried.
One way they found was to hug in congratulations a teammate who had scored a goal.
After several weeks, the experimental group and control group were tested again. The experimental group had a better mood on average. They were happier and less likely to be depressed.
In one study with results published in 2005, various men and women were instructed to talk, watch a brief romantic film and then hug for 20 seconds. After the 20-second hug, their levels of oxytocin were higher than before and women's blood pressure was lowered. This was true of both the women in a "loving relationship" and of woman who were in a relationship not as loving.
A person with higher oxytocin levels tends to have higher satisfaction with life in general and with their partner. In fact, scientists have done experiments with men in which some of them were merely instructed to kiss their partners more frequently. The result was that they had lower perceived stress, lower serum cholesterol and higher satisfaction in their relationship.
In one study, 404 healthy adults were questioned about their social support and hugs per day. They were then exposed to the infectious agents causing the common cold or the flu. Of those who got sick, those who hugged more frequently than the median of the group prior to exposure had less severe symptoms.
Another study checked on the physiological results of "warm partner contact," meaning, hugging and kissing a romantic partner. Those who did so were happier and less irritated afterwards and certain serum proteins were higher. The study authors speculate that warm partner contact is good for one's health.