This is fascinating, each of us are individuals and we each have a unique combination of several
hundred genes corresponding to our immune responses which protect us from some diseases and
not others, everyone is different and no one is the same (*except for monozygotic twins). No
one person is resistant to every disease known to man.
Our sense of smell (olfactory system) is so highly evolved that we will find someone’s’
smell to be pleasant if they are resistant diseases that we aren’t. Our sense of smell and
brains are wired to detect potential partners who are resistant to different diseases. This
is important because when one person is sick the other might be healthy, in addition
children will inherit a more diverse set of genes from their parents (protecting them from
form more diseases than either parent alone).
The relationship between immune system genes and attraction (mate-pairing) is not exclusive to
humans, it has been reported for many vertebrates including fish, birds, primates. Please refer
to our reference list for dozens of research papers describing this phenomenon.