When To Trust Your Gut Instinct (& When To Ignore It)

'Gut instinct' is a term that holds an almost mystical quality, speaking to a sense we might feel for what is right or wrong: an action, a decision, a relationship. 'Always trust your gut' is a well-worn advice trope, the implication being that if we really tune into ourselves, we will 'just know' that something (or someone) is or isn’t right. But what exactly is this inner force we call instinct? 

"Instinct is when physiological signals change quickly in response to different stimuli, with or without the conscious awareness of the properties of those stimuli," says Professor Sarah Garfinkel, a cognitive neuroscientist based at University College London. "A capacity to tap into and be guided by those signals gives us a route to gut instinct, which bypasses higher-order awareness mechanisms that don’t yet have access to that information." In other words: "Sometimes the body knows before the mind does." 

A few years ago I saw a squirrel lying prostrate in the road. It had been hit by a car and was gasping for breath. My instinct in the moment said: I can save you. I picked it up and made a vague attempt at CPR with two fingers on its tiny chest but its head quickly flopped to the side. It was over. It might sound ridiculous but I think about the look in that animal’s eyes, watery and full of terror, often. Did my instinct to rescue make its final seconds of life, in the strange hands of a human being, unnecessarily frightening? Should I have walked on and let the inevitable happen? The urge to act was strong. I felt it in my gut. 

With the word 'gut' we situate an emotional response firmly within the body and, at least linguistically, detach it from any robust, 'proper' analysis that might happen in the head. But the idea that mind and body responses are separate (an ancient philosophical idea called mind-body dualism) is long debunked. Instincts, or gut feelings, are not a separate experience: what we feel in the body is the result of complex processes that happen in the brain.  

The brain is a prediction factory. It is always comparing current experiences (and all the sensory information they give us) with previous experiences, knowledge and memories. It wants to predict what might happen next so we can deal with it in the best way. This is what scientists call the predictive processing framework. Intuitions, or gut feelings, occur when the brain has made a good match, or mismatch, between what is in front of us and our cognitive models – our software programmes, if you like – and applies meaning to what’s happening. The brain sends signals to the gut, which is teeming with nerve cells. So those butterflies-in-the-stomach feelings (good or bad) are a result of cognitive processing. This signalling happens without our conscious awareness. 

Gut feelings, or intuitions, however, are not dumb responses that always need to be sorted out by rational thinking. They are part of how we process information. But the rapid assessments we can make – especially about other people (using subtle, perceptive cues like facial expressions or gestures to gauge their intentions: harm or help?) – are subject to error. The human brain is absolutely loaded with biases. Confirmation bias – probably the most common of them all – leads us to scramble for evidence that confirms what we already believe but not all of our assessments will serve us well. That uncertainty is hard to sit with and is why we so quickly try to ascribe meaning. Sometimes, that meaning is danger. 

Stephanie, who is in her 30s, tells me how, while travelling solo around America, she got talking to a man at a truck stop in North Carolina about how she’d been unable to access the internet and wanted to email family and friends. "He told me he was building a group of log cabins not too far away and had internet access there. He was quite old and gentle-seeming, so I thought: Okay. I followed him in my van down the road. When he parked beside a single trailer and got out of his car, my hackles went up. There were no log cabins." 

Stephanie got out. The man walked into his trailer. "You can check your emails inside," he said. She started to panic. Her instinct said: Don't go in. "I asked if the log cabins were nearby and said I’d love to see them first. He suddenly looked angry and said, 'Okay, hang on,' and stepped inside." Stephanie ran to her car and sped away, convinced he was going to tail her. "In hindsight, I feel silly for going. But that was the most powerful gut feeling I’ve ever had." In this context, Stephanie’s gut feeling– based on cognitive models about how a dangerous man might behave – spoke to survival instinct. 

When we’re making decisions or entering different kinds of relationships, our gut feelings – although important – can be a fickle guide. "The problem is that our recollection of past memories and contexts might not always be accurate and is often dependent on our current emotional state," writes Dr Pragya Agarwal in her book Sway: Unravelling Unconscious Bias. Self-confidence seems to be a key factor in how easily we can make decisions.

Thirty-one-year-old Nat messages me on Twitter to this effect: "Whenever I try to identify my 'gut feeling' I end up feeling like I must have two guts, like a sheep or something; my innards are no less indecisive than the rest of me."

"When something feels 'off', whether it’s on a date or a specific work-related situation, I feel it physically. That doesn’t mean I’ll know what the problem is, or that I’ll act on it right away, but I feel pulled or repelled by certain things," says Naseem, 28. "That sense of 'everything will be fine' does lend itself to impulsive behaviour that isn’t healthy. A lot of it probably comes down to feelings of low self-esteem. I don’t believe in my capabilities so in order to get anything done I tune out the active thinking that psyches me out and let my gut take the lead." 

For people who live with anxiety or who are recovering from trauma, trusting the messages from a body that always feels like it’s on high alert can also be challenging. (As someone whose anxiety always lives in the gut, I know this too well.) Long-term stress can mean our fight-or-flight response does its thing on a hair trigger. "I describe an overactive stress response to clients as being a quick-and-dirty memory system," says Dr Anne Golden, a counselling psychologist in Dublin. "It’s like a very touchy smoke detector; all you’re doing is making toast but the alarm feels deafening." 

One of Professor Garfinkel’s research areas is interoception: the sensing of physiological signals originating inside the body, such as hunger, pain and heart rate. The nexus of gut feelings. "Our organs are in constant, dynamic communication with our brain yet it would not be adaptive to be distracted by them all the time," she explains. "But interoception is linked to survival; signals arise to the surface – if we’re really hungry, thirsty or scared – and infiltrate conscious awareness, because we need something." 

Interoception is one of the fastest moving areas of psychology and neuroscience. Scientists have shown that our sensitivity to interoceptive signals is linked to how we regulate our emotions. There are links between poor interoceptive ability and depression. Conversely, people with anxiety have reported being highly aware of their interoceptive signals – but they might not read the signals accurately. 

"A broader point about interoception is that the signals in our body are not fine-tuned. It can be hard to map them precisely onto different states," says Professor Garfinkel, who became interested in the field after working with people with PTSD. Small changes in heart rate might be read as more dramatic than they are. Twinges in the belly might be catastrophised as pending gastric disaster. These rapid interpretations of physical signals can ratchet up panic: that touchy smoke detector Dr Golden speaks of. 

This makes me think about the rapidly growing market for body-tracking interventions (at-home blood-testing kits from companies like Thriva or Bloom Diagnostics, whose PR teams email me on the back of nearly every health-related piece I write) and the murky world of female hormones, for which we are constantly being sold new products or apps as navigational tools. 

In 2019 I wrote an in-depth investigation into the functional medicine industry, which relies on sophisticated-sounding tests for everything from vitamin deficiencies to 'hormonal imbalance', gut parasites or mould sensitivity. I was astounded by how readily pseudoscience is wielded (often by people with good intentions) to confused, vulnerable people. The tests and laboratories used by functional medicine practitioners are shrouded in controversy. The smallest nuggets of data from tiny-cohort studies are turned into sellable narratives that result in someone spending hundreds and thousands of pounds on consultations, tests and supplements in a bid to confirm the belief that something is wrong.

Submitting to testing, or tracking our bodies in various ways, has become a proxy for self-care. This is an understandable response to biases in a healthcare system that routinely dismisses and diminishes women’s experiences. I wonder, though, if the tools capitalism offers us are divorcing us from instinct. Our bodies are designed to self-maintain. Disease, illness and pain are horrible facts of life but the path of inward fixation is slippery. If we have a gut feeling that something is wrong, it shouldn’t be ignored – but it can also be vulnerable to exploitation. Once you start digging and have invested money in people offering answers, it can be hard to stop. In this way, we change how the brain processes the body. It becomes a site of discomfort that needs constant interrogation. 

"I don’t believe there is much to gain from people fixating on their body in this way; it taps into self-monitoring mechanisms associated with anxiety," says Professor Garfinkel. "I’m worried that we are less able to follow our instincts, partly because we’re told that what will make us feel better is really understanding our bodies and pampering ourselves. But these are capitalism’s answers, because it sells products. What increases feelings of wellbeing and satisfaction more than anything is human connection." 

I hear this and agree but it can be hard to know where to draw the line when myths and misinformation in areas like women’s health have caused much unnecessary shame and suffering. Particularly when human connection between doctor and patient, and the space to be heard, has been lacking. Knowledge is power but perhaps too much knowledge – or the highly marketable idea that we shouldn’t be comfortable just existing in our bodies when there's so much to question – is a trap we should be aware of. 

On the matter of human connection, the idea of gut instinct often comes up within romantic relationships. We are, as Dr Golden says, "fed a lot of trite stuff" from pop songs and romantic films about instinct and how when you know, you know. There is beauty in feeling able to just be with someone: the feeling of safety within the body that arises in proximity to someone you love and trust. But feeling safe with another person can take time and personal work. When we meet someone, our entire life experiences collide: our early caregiving relationships, our attachment styles, our values, our hopes for the future. It isn’t always straightforward. 

When we are vulnerable, as we are when we fall in love, we can be easily triggered by someone’s behaviour – particularly if it matches with a cognitive model we have for what love looks like. A common source of tension in romantic relationships is a clash of attachment styles; the push-pull dynamic that can happen between anxious and avoidant-attached people, for example. Both parties can be triggered by the other for seeming to need too much, or too little, and experience significant anxiety around ways of connecting. 

If I have an anxious attachment style, I might feel a visceral anxiety around perceived rejection or disinterest. If I have an avoidant attachment style, I may feel easily suffocated by attempts to connect or the need to withdraw from difficult conversations. But my emotional triggering may speak less to someone’s behaviour than it does to my deeper emotional landscape. An analogy used by Gabor Maté, author of When The Body Says No, also stays with me: "What is a trigger? If you look at a weapon, the trigger is a very small part of the mechanism, isn’t it? What there really is, is a weapon that is loaded, ready to fire, and it’s got ammunition in it. That’s you." 

Dr Golden offers another important point: "There is something about the reality of being vulnerable and that is that sometimes it is easier to be angry than it is to be afraid." In this sense, immediate bodily responses won’t always be accurate – or self-compassionate. We can quickly summon painful core beliefs like 'I am unlovable', 'I am too much' or 'People always need too much from me'. These beliefs are made when we are young, in relation to how our caregivers tended to us. We deserve, as adults, to challenge them, and personal therapy can be a helpful way to inquire why people can 'make' us feel the way we do. In time, we can learn to notice when those core beliefs are triggered and decide whether we need to react – or allow the wave to roll away.

In all our relationships, and in the decision-making we do in our day-to-day lives, the reality is that we are never just going with our gut feeling. Unless we are in a dire emergency, there is always some higher-order thinking casting influence – even unconsciously. Gut instinct is not a cosmic force but it can give us signals about our responses that may be important to consider. Even if, in hindsight, we have to accept that immediately reacting to embodied emotion isn’t always helpful. I do think I should have left the squirrel alone.