I think, it is not necessary to explain, why in general people embrace each other. Let's try to look at "enclasping" from other, especially scientific point of view.
On January 21 in the 70th years of the last century in the West started celebrating Day of embraces. Today this day (and not only in this, and and in any other) on the street it is possible to meet people with plates "Give me a hug!" ("Embrace me!"). Than such attractiveness of embraces strange at first sight speaks?
The first reason intimate – embraces help us to express the feelings. However there are also others, the reasons less known to most of people. First of all, embraces promote emergence of feeling of safety in us (Desire to be absolutely safe, truly?). Remember how in the childhood we liked to cry and always ran to mother, demanding embraces and protection. After that to us it became good, there was a feeling of safety.
Secondly, the person is so arranged that constantly needs tactile requirements, more precisely, their satisfaction. In other words, we cannot simply live without "obnimashka"! In blood of the person gipotalamus oxytocin which promotes good health and mood for all day throws out a special hormone.