Here are some kissing facts that might make you think twice about the procedure we go through every time we feel close to the opposite sex.

Some scientists have suggested that kissing might be a ritual that's evolved in us humans for millions of years, all the way back to the primates. Primates such as chimpanzees feed their young by chewing the food first then mouth feeding their infants. So kissing might be another way we humans express love and affection to one another.

Since the evolution of kissing, this way of expression appears to be addictive. Our lips have the thinnest layer of skin than any other part of the human body and are packed heavily with sensory neurons. So when kissing occurs, both tongue and mouth send messages to our brains and bodies, releasing certain chemicals within us and creating a pleasurable mental and physical sensations.

Here are a few more kissing facts. Studies done in recent times compared hormone levels in 15 couples before and after kissing. Test results were also recorded before and after the couples talked with each other while holding hands. What resulted from these studies were that levels of one hormone called "oxytocin" rose in the males and decreased in the women, throughout both tests - oxytocin is a hormone that's involved in social bonding. This suggested that the females probably required more than kissing to feel the bonding and sexual excitement that occurred in the males - how's that for kissing facts! It is only speculation at this point but according to many surveys taken, women seem to require a little bit more to get turned on, for instance - a romantic setting or seductive conversation.

However, one thing proved true for both sexes during this experiment and that is, stress levels of both the males and females dropped when they kissed. Could this suggest that we should be kissing more to avoid a heart attack?

Further studies have shown that kissing can also be addictive in that the same reward centers in our brains are getting stimulated not unlike people who use drugs such as cocaine. Rational thoughts dissipate from our minds and primal urges and desires tend to unfold.

Although these kissing facts have not been backed up by solid evidence, we could see how the results of the tests have mirrored our own emotions and behaviors. To us, kissing is associated automatically by the emotion called "love", but could this feeling merely be a result from millions of years of evolution?