One of the most popular theories about why we greet each other with a handshake explains that it's a way of showing that we're unarmed, as a sign of peace. But another theory alludes to a supposed biological origin, to detect the other's chemical signals, as dogs and other animals do when they sniff each other, but, due to our social conventions, in a slightly more subtle way. A Weizman Institute of Science experiment with 280 volunteers, published in 2015, showed how many participants brought their hand to their face and discreetly sniffed it after shaking hands with a stranger who had been introduced. According to the authors, they were actively seeking social chemical signals. Previous studies have suggested that human chemical signals play a role in mate selection. They convey fear, alter brain activity, and synchronize women's menstrual cycles. Perhaps the smell of our hands says more about us than we thought, apart from our greater or lesser fondness for soap. Now, researchers at Florida International University have discovered that the aromatic compounds in the palm of the hand can be used to predict a person's sex in an almost infallible way. Related News standard If Morten Meldal, Nobel Prize in Chemistry: "Falling in love is chemistry, being hungry is chemistry, everything is chemistry" Judith de Jorge The Danish researcher is one of the fathers of 'click chemistry', a simpler, faster, and greener way of joining molecules to create new drugs or materials. In the new study, published in PLOS ONE, Kenneth Furton and his team used an analytical technique called mass spectrometry to analyze the volatile aromatic compounds present in the palms of 60 people, half men and half women. After identifying the compounds in each sample, the team performed a statistical analysis to see if they could determine the sex of the individual based on their odor profile. They succeeded 96.67% of the time. A Criminal's Trail As the authors explain, robberies, assaults, and rapes are crimes that are often carried out by the perpetrator's hands and therefore have the potential to leave valuable traces at the crime scene. Existing research on human odor indicates that odor compounds can also reveal someone's age and racial or ethnic group. With further validation, the researchers continue, the chemical and statistical analyses presented in this paper could be used to uncover many details about a potential perpetrator solely from the smell of their hands. MORE INFORMATION news If There's a huge 'gravity hole' in the Indian Ocean—and scientists finally think they know why news If James Webb observes one of the first strands of the 'cosmic web' "This approach to analyzing hand odor volatiles can be applied when other discriminatory evidence, such as DNA, is lacking and allows for differentiation or characterization of classes, such as sex, race, and age," the researchers state.
