Science & technology
Smell you later, alligator
Friends is seems often have similiar body odours
Dogs greet other dogs nose-first, as it were -- sniffing each other from fore to (especially) aft.
People are not quite so open about the process of sniffing each other out.
But the size of the perfume industry suggests scent is important in human relations, too.
There is also evidence that human beings can infer kinship, deduce emotional states and even detect disease via the sense of smell.
Now, Inbal Ravreby, Kobi Snitz and Noam Sobel of the Weizmann Institute of Science, in Israel, have gone a step further.
現在，以色列魏茲曼科學研究所的Inbal RAVREBY、Kobi Snitz和Noam Sobel在這方面的研究更深入。
They think they have shown, admittedly in a fairly small sample of individuals, that friends actually smell alike.
They have also shown that this is probably the case from the get-go, with people picking friends at least partly on the basis of body odour, rather than the body odours of people who become friends subsequently converging.
As they report in Science Advances, Dr Ravreby, Dr Snitz and Dr Sobel started their research by testing the odours of 20 pairs of established, non-romantic, same-sex friends.
To do this they employed an electronic nose (e-nose) and two groups of specially recruited human “smellers”.
The e-nose used a set of metal-oxide gas sensors to assess t-shirts worn by participants.
One group of human smellers were given pairs of these shirts and asked to rate how similar they smelt.
Those in the other group were asked to rate the odours of individual t-shirts on five subjective dimensions: pleasantness, intensity, sexual attractiveness, competence and warmth.
The e-nose results and the opinions of the second group of smellers were then subjected to a bit of multidimensional mathematical jiggery-pokery (think plotting the results on a graph, except that the graph paper has five dimensions), and they, too, emerged as simple, comparable numbers.
All three approaches yielded the same result.
The t-shirts of friends smelt more similar to each other than did the t-shirts of strangers.
Friends, in other words, do indeed smell alike.