In general, some people's fragrances are more alluring than others.
It’s been established that guys who have a diet heavy in fresh vegetables smell more desirable to women.
People often smell better when they are healthy.
However, since humans generally have a weak sense of smell, kissing has significant psychological significance.
We are drawn to folks with various immune systems.
Lower voice might be a sign of greater size and potential for better wilderness survival.
We feel good around people because of these "feel good hormones," which elicit emotions of security, cosiness, and comfort.
Physical contact also has a tendency to hasten the process (where it is welcomed, of course).