We Are Out Smelling Ourselves


Your coffee smells much better than mine. I'll bet it tastes better too. Yeah, rub my nose in it! You know we shouldn't be amazed we can tell subtle differences in odors because a new study reveals we can distinguish between an astonishing trillion scents! That blows away our old assumptions!

We've all been going by a 1920s study that said humans can only discern ten thousand scents. Compare that with our ability to discriminate up to eight million colors and it appeared our eye sight outshined our sense of smell.

In reality, scientists suspected the estimate on our olfactory capability was a bit low. We have about four hundred smell receptors that work in concert to perceive smell. Natural odors are mixtures of components at different ratios. For example a rose's scent is a mixture of about three hundred components.

In the new study, 128 different molecules were used; each a distinct smell. They were mixed so that each mixture contained various concentrations of ten to thirty scents. Each study participant was given three mixtures at a time with two identical ones and the third being different. Each person smelled about five hundred odorants. What researchers observed is that for people to tell the difference between the vials, the mixtures had to differ by at least 49 percent. Or you could turn that around and say two vials could be 51 percent identical and people could still tell them apart.

That's impressive and even more so when you extrapolate the numbers to find we can distinguish between at least one trillion scent combinations. Now we can't identify a trillion scents, but that's still quite good. Makes me wonder just how crazy amazing my dog's sense of smell is!