From almost as early as we’re able to count, we’re taught humans have five senses: taste, touch, smell, sight and hearing. The comic book concept of ‘super-senses’ only underscores that belief. The idiom about a ‘sixth sense’ doesn’t help, either.
In reality, five is just the start. In the course of writing this article I have employed far more. I am touch-typing, which involves touch, yes, but also a limb-location known as proprioception: I don’t need to look to know where my fingers are going to land. My heartbeat is quickening as the deadline approaches, too. Knowing that is thanks to another sense, cardiac interoception. It’s sunny outside, meaning I feel warm, that’s thermoception. And I’m getting hungry, but how do I know my stomach is empty? Because I can sense it, of course.
Revealing and celebrating our myriad other senses – roughly 32, by the author’s count, though it’s up for debate – are the chief concerns of a fascinating new book, Super-Senses: The Science of Your 32 Senses and How to Use Them, by the science writer Emma Young. The idea that we have five, she argues, is not only simplistic but it’s also holding us back. "There isn’t a sense scientist around today who’d say we have five. That model is because it’s easy – shut your eyes, you can’t see, cover your nose, you can’t smell. In fact there are all these other senses that are fainter, but we use every day without even being aware they exist," Young, 47, says.
Being aware of those senses helps us to better comprehend our bodies and in turn live a more enriched, healthier, happier life, she tells me.
"Before I spoke to you, I had this really irritating phone call and my heart’s still racing because of it," she says. "I’m sensing that, because it really does influence your state of mind. You don’t have to always be consciously aware of [all the senses pulsing through us], but it helps us understand ourselves."
One of the more common examples of somebody experiencing an extra sense is instinct: an innate response to certain stimuli. "Because our brains are so complex, when we react to a situation and think about the answer we neglect to realise all the unconscious processes that are going on and a lot of those rely on sensory input," Young says.
An example she cites in the book involves financial traders, who frequently talk about relying on ‘gut feeling’ to quickly assess risk. "In a threatening situation," she writes, "blood is diverted away from the intestines, while adrenalin makes the involuntary smooth muscle of the intestines relax, and stretch receptors in these muscles detect this." Our brains learn these changes, eventually coming to predict situations in which they tend to happen.
If somebody tells us to "trust our gut", then, it’s not an old wives’ tale: our bodies can draw on sensory data and help us to make the wisest decision.
How to listen to your heart
Young says paying attention to our senses can help us to calm down. In recent years, the number of people being diagnosed with anxiety has soared. One thing that might bring comfort, Young argues, is to understand what is happening to our bodies in that moment of panic.
"If you’re feeling anxious then your heart is racing and there’s a part of your brain that isn’t necessarily the conscious part, which receives that and delivers it as anxiety. One idea is that if you can get people to be better at tuning into those signals, you can help to reduce your anxiety," she says.
One strand of research proposes that people who feel anxious should sit quietly, then see if they can feel their pulse within their body (without touching their wrist to check), then count how many times they think their heart beats in a couple of minutes.
"Then," Young says, "if you have somebody around who can actually check your pulse, you can find out how accurate or wildly inaccurate you are. The idea is that the more you do that, getting feedback data on how accurate you’re estimating it, you get better at it over time, which in theory should reduce your anxiety."
"The great thing about the senses is that virtually all of them can be trained, and improved through training," Young says. Evidence has shown that obese people have less sensitive taste cells – and this effect can be reversed with weight loss.
But what about people who are especially sensitive, to the point of being described as having a ‘gift’? The book gives some extraordinary examples, including a nurse who could smell Parkinson’s disease, but she says the most common occurrence is probably those people who are effortlessly good at PE.
"We all know people who are incredibly able at all sports," she says, and while those people may be loftily called ‘gifted’, they are often lucky.
The main sense involved in sports is proprioception, the same as my touch-typing, or any of us being able to walk downstairs without needing to look at where our feet land.
"Those proprioceptors tell you exactly where your body is in space, and there is a big spectrum of sensitivity within those receptors," Young says. Having excellent proprioception can mean you’re naturally better than others at kicking and controlling a ball.
The broad theme of Young’s book, as she dances between anecdote, case studies and science theory, is that we are all wired differently. Clumsy people, sweet-toothed people, people who cannot stand loud music in bars, even people who claim to see ghosts, are all the result of our diverse sensory make-ups.
One example is that the notion of something seeming ‘fishy’ isn’t just a linguistic quirk, fish really does make people more suspicious. One experiment Young found revealed that people identified more errors in a piece of text lightly sprayed with fish oil than one that was odourless.
In knowing about these abilities, it makes even us mortals feel like we have super-senses. "What people should take from this, really, is just that we should appreciate that we all have different experiences, to have sympathy with others, but also get to know our own senses," she says, "because from our career choices to who we’re friends with and how we regulate our emotions, they affect everything."
The Daily Telegraph