Part of the show Science of Seduction, Pheromones and the Food of Love
Steve in Harwich asked:
When someone meets someone else, is there a special hidden smell that couples have between them, so that if you were then to split up and meet someone else, you'd have that same kind of chemistry? Is that how you know someone is the right person for you?
There's possibly some basis to this. There has been some evidence from quite special populations of Hutterites in the United States that the family trees aren't decided by random assortments of pairings. Instead it seems that they are actually biased by genetic identity, and this could actually be due to the sense of smell.