Touch is a constant source of embarrassment for many of us. One movement of the hand can bring us closer, or it can destroy the hope of rapprochement.
Psychologists at Oxford University (Great Britain) asked volunteers from Finland, France, Italy, Russia and the UK to mark on the body diagrams the zones in which the touch of other people (depending on the degree of proximity and kinship) is most and least acceptable for them.1. Despite some differences (for example, the Italians were expected to be more liberated than the Russians), the forbidden zones are approximately the same for everyone: this is the bottom of the body to the level of the abdomen. Interestingly, women indicated wider limits of what is acceptable than men. One explanation that the authors of the study see is that women traditionally pay more attention to maintaining social connections. And touches for most of them (primarily in relationships with close and familiar people) are a sign of location and sympathy.
1 PNAS, 2015, vol. 112, No. 45. Schemes indicating the zones can be found in the appendix to the article.