Small differences in olfactory receptor genes, which are extremely common in humans, can affect the way each receptor functions. These genetic differences mean that when two people smell the same molecule, one person may detect a floral odor while another smells nothing at all.

What makes odors smell different from each other?

The way a person perceives smells comes down to her particular arrangement of amino acids. A difference of a single amino acid on one gene can cause that person to experience a smell differently than someone with another amino acid. ... Each of those receptors were slightly different, on the order of an amino acid or two.

Why does everyone have a different smell?

While it can change depending on our diet and health, a lot of what makes our smell unique is determined by our genetics. Our body odour is specific enough, and our sense of smell accurate enough, that people can pair the sweaty T-shirts of identical twins from a group of strangers' T-shirts.