Needless to say physical contact or gesture, one way or the other, is essential to interactions between humans.This may be mere touch, a pat on the back, hug, caressing. Shaking hands is also a physical gesture. Kiss is most intimate form of expressing love and affection. Kiss is not merely a display of love  between a man and woman. There are different types of kisses- lip lock, on cheeks, hands and even flying kiss without any touch. Kiss is not only as expression of romantic love but also an affection to a kid, sister or mother. Usually you kiss a child on cheeks. Lip lock is usually for couples- married or otherwise.

Romantic kiss 

There is also tradition in some countries for kissing as a social function. When you meet a friend or relative or bid good bye, you may express your good wishes in shape of kiss.  

The word 'kiss' is derived from Old English 'cyssari' which in turn is a variant of 'coss'. 

Needless to say, kiss is inseparable from literature especially romantic poetry. There is an Urdu couplet- "I kissed her cheeks in dream only. Even then these got red hot'. Kiss is also essential in movies- especially the romantic ones. For long, censor would make drastic cust of kissing scenes. Now the Board is more liberal. But what goes unnoticed is its role in cultural and religious traditions. The Nineteenth century anthropologist Cesare Lombroso views that maternal kiss came first.  Lovers' kiss followed. Among Andaman tribals, kiss was just an expression of affection towards children. Persians used to kiss on hands. There is custom of a couple kissing in church just after wedding.    

There is reference to kiss in Old Testament. The 'song of Solomon verse reads as:

Let him kiss me with the kisses of his mouth;

For thy love is better than wine 

There are many religious rituals that involve kissing. For example: Kissing the Pope's foot or a bishop's ring. There is also a religious custom in Judaism of kissing prayer book. There was a church custom to kiss the baptized after ceremony was over. Some times, kiss was used as a form of salutation to saints and religious heroes.  According to Saint Cyril, "Kiss is the sign that our souls are united and that we banish all remembrance of injury'. 'Holy kiss' was inalienable part of occasion like baptism, marriage, confession etc. 

There was a tradition of Kiss of peace. When the enemies reconciled and made peace, they expressed this with kiss as a token of peace. This was called 'kiss of peace'. Also before proceeding on war, knights would give each other 'kiss of peace' before departing for combat. The kiss of peace signified that that had forgiven one another for all wrongs- real or supposed.

Kiss was also used to respect inanimate objects like image of the crucified, sword etc.  Here are two images: Joan of Arc kissing sword of liberation and a kiss on the crucifix. In our day to day life, also we see some kissing a book or putting this close to forehead as a respect.      

Joan of Arc kissing the sword of liberation 

Kiss on the crucifix 

Role of kiss is thus not restricted to love and passion. This covers every aspect of life- romance, culture, literature, cinema, religion. This is also depicted in ancient Indian art- as can be seen in Konark, Ajanta and Khajuraho. 

All images from wikipedia