The kiss. Throughout history, the kiss has been the topic of art from cinema to pastels, and the big question when there is sexual tension, "So, did you kiss yet?".
Interestingly, the kiss means different things to different people, especially traditional genders, of male and female.
Females tend to place much more weight into kissing, as a way to define if their partner is worth pursuing more intimately or deeply. In a study in 2013, over 50% of women ranked kissing as very important and more important than other forms of romance.
For men, in the same study, less than 50% of them considered it important.
Hold on though, not so fast with assumptions.
Men felt kissing was the gateway to intercourse and, important in that respect. However, men in the study also felt that if they could have intercourse without kissing, that was fine also.
Women on the other hand, felt that kissing was integral as a deciding factor of both intercourse and, a deeper relationships and, felt that without kissing, they were not as interested in intercourse emotionally.
This means that those couples who do not spend time kissing, the female is potentially not as interested in intercourse, as the male might thing; regardless of her alleged responsiveness externally.
What makes a kiss so alluring?
A kiss brings you right in close to your partner. Everything from teeth and hygiene health is exposed, to hormone levels and messages, and the feel and health of the lips and skin. All of this gives millisecond messages of "is this person a viable mate".
Adding to this, is the increase in trust, reinforcing feelings of intimacy and affirmation of being wanted and valued. As you can see, a kiss is not "just" a kiss.
The most interesting study that I found, as from the Western Journal of Communication in 2009, which proved that increasing kissing over six weeks, lowered stress levels and, cholesterol. The couples who increased hissing by just 15 minutes each week, also showed stronger bonds and self-reported happier relationships.
So, while kissing seems to have no direct reproductive benefit, it clearly shows that it is sexually and biologically, a positive experience for couples to enjoy.
Pucker up :)