What's in a Kiss?

A kiss involves two of the most sensitive parts of the body, the lips and tongue. Although they take up very little of the body's surface, 30 percent of the work of a temporal lobe is on the sensation there.

When kissing, the brain produces endorphins, which make us feel happy. For women, a kiss releases a large amount of oxytocin and boosts the level of affection for the partner. For men it increases the testosterone level and arouses them sexually. That is why men often regard kissing as a step toward sex while women identify through kissing whether the partner is emotionally and sexually compatible.

Women can identify whether the partner is a good match by the taste of testosterone in men's saliva. Time magazine reports that women can make a judgment on whether they are genetically compatible and can produce a healthy baby with the partner while kissing.

The belief that kissing can help people lose weight is not totally groundless. A kiss consumes about 12 kcal, which is equivalent to a glass of tomato juice, half a cucumber, or three to four cherry tomatoes. There is research that suggests a kiss produces a special element in saliva that kills caries, or chemical substance that fights against various infectious bacteria.