Our noses are more sensitive than we give them credit for. In 2014 neurobiologist Leslie Vosshall, conducted a study that proved humans could smell 1 trillion scents at a time. Our brain cannot process this many smells at a time though so a lot of this detection happens subconsciously. This is because the olfactory nerves don’t go to the brains thalamus they go to the cortical areas. This is why emotions or memories can be triggered by certain smells. You could be influenced by the sunflowers at your workplace everyday to express a certain emotion and not even realise it. An example of this could be if someone broke into your house and they had a strong body scent that you couldn’t quite explain. If you were to randomly come across someone who has the same scent this would subconsciously trigger an emotion in you that may make you not trust them. Books like ‘The Handbook of Second Language Acquisition’ by Alison Mackey conclude that people are able to detect a person’s specific scent when blindfolded using a “line up” method 75% of the time through the use of brain imaging technologies.
A 2015 study in Israel conducted by Noam Sobel on 152 volunteers revealed that sniffing the chemical traces of DNA after a handshake can subconsciously help us determine how that person is feeling and whether they are romantically compatible with us. “I am convinced that this is just the tip of the iceberg, this is just one more instance where chemo signalling is a driving force in human behaviour,” says Sobel. Charles Wysocki from the Institute for Chemical Senses in Monell in Philadelphia said this “fits with the general idea that there is a lot more chemical communication going on that we are unaware of.”
According to Lundstrom, a neuroscientist at the Karolinska Institute in Sweden, the scientists are still seeking additional explanations behind this, however at this stage it is obvious that the human smell influences our brain differently from other scents. A lot of other olfaction researchers like Lundstrom imply that emotions have their own unique scent and that these emotions are contagious. This is evident in European research evidence from 2015 whereby Jasper de Groot, a psychologist from Utrecht University concluded that participants were able to assume the emotion of test subjects just by their scent. His findings have been published in scientific journal ‘Metabolites’. He continues to add that this is why detecting the body scent of stressed individuals increases our vigilance and sniffing people who are experiencing disgust makes us express disgust in ourselves. For example, through our facial expressions.
A journal article from 2009 by Strey, Fredrick, Savoy, Cox and others proves that fear is contagious through the use of fMRI scans, where people sniffed the sweat of first time parachute jumpers and were able to detect their fear. They proved this through scanning the left amygdala, which is where emotions are processed. The left amygdala lit up when sniffers smelt the parachute jumpers, indicating that fear can be contagious. The next time someone says that you are an empath you can explain this article to them to give them the scientific reasoning behind it.
When it comes to choosing a romantic partner our brain is wired to smell whether our immune system will be compatible with the potential partner or not. An experiment in the journal of Psychological Science in 2014 concluded that people could detect illness through body odout. As humans, we are wired to do this in order to chooses a partner who has different health issues to ours. If we choose a partner who has the same health problems as ourselves then this may not be the best way to pass on our genes, therefore we choose someone who has a compatible immune system. Researchers from McGill University in Canada used neuroimaging to find proof that smelling the body odour of someone closely related activates the dorsomedial perfrontal cortex, a part of the brain responsible for recognising family. Research shows that people prefer partners who are somewhat genetically related, but not too related. “Biologically it makes sense, we want to protect our gene pool. But it is not so much picking the best partner, it’s deselecting the bad partners.” Lundstrom says. His words of advice are to “Listen to your inner voice, because your inner voice might be your nose telling you what to do.” So if you find yourself attracted to someone in particular, just remember that it is not just due to change, it is because our brain has already picked up that we are compatible with that person. The same pattern is noticed in mice and rats however the main scent they pick up on before choosing a genetic match is urine.