The study also suggests that while we kiss, we examine the level of the person’s health through their breath and taste. Naturally, bad breath or taste can potentially signal health concerns. Furthermore, when we kiss we also exchange an oily substance called sebum that is produced by the body’s glands.
We exchange this substance by touching the skin around and inside the mouth. And this substance contains pheromones, which reveal valuable information about a person’s biological makeup. In other words, it shows things that the 2 people kissing have in common.
Scientists also suggest that this substance reveals hormonal information which tempts the brain to wonder whether this person is healthy enough to start a family with. This is, of course, done subconsciously, and we don’t really think that we’re analyzing our partner, but that subconscious part of our brain massively impacts the way we behave, even though we don’t really understand how it works.
What’s interesting is that more than 60% of people admitted that they lost interest in a potential relationship after a bad first kiss. The brain literally analyzed the kiss and sent a message that this person is not the one, prompting the person to end the relationship. Kissing helps improve the attractiveness, but when we’re not happy with the kiss, it can make us feel repelled by our partner.