The Bizarre Evolutionary Anomaly That is Travel Sickness

By Becca Caddy on at

They say it’s not about where you’re going, but how you get there. And that you should enjoy the journey or the ride as much as the destination. But you know what makes that really hard? Feeling like you’re actually about to die when you’re travelling anywhere. At any time. In any conditions.

Sickness, lots of sweating, extreme tiredness, yet with an inability to keep yourself even remotely still, and a complete loss of cognitive abilities. Welcome to the always nauseous and constantly fucking twirling world of travel sickness.

Charles Darwin himself put it the best when he famously wrote to his father, “The misery I endured from sea-sickness is far, far beyond what I ever guessed at.” I feel you Charles, I really do.

It doesn’t matter whether it’s planes, cars, rollercoasters or trains. Essentially anything that moves feels like it was specially designed to screw me over from the inside out. Even passionate swirling dances and silly spins on an office chair have been known to set it off. And let’s not even talk about the embarrassment of having to leave the cinema when watching anything from the ‘found footage’ genre (I’m looking at you, Cloverfield).

The worst part is, only people who get travel sick really ‘get’ it (and that’s about a third of us). It’s a little like bad hangovers (which I also get too, thanks genetics!). Most people think that, on some level, you’re just a big drama queen who is invariably faking it for attention. (Because no attention is better than attention when you’re sweating buckets and throwing your guts up, FYI.)

Throw up overboard after an hour on a catamaran, “Big baby, have some ginger!”, get a headache so bad on a fairground round you can barely see, “You must be scared, you big scaredy, breathe!”, feel like your brains are being slowly squeezed out of your tear ducts, “You’ll get used to it, try looking forwards!” As if I haven’t tried every lame, condescending, ginger-infused remedy in the book.

But when you start reading around about travel sickness, everyone’s lack of knowledge and wishy-washy attitude begins to make more sense. Because no one knows what the hell they’re talking about. More than once throughout my research for this feature I saw it described as an evolutionary anomaly. Which doesn’t fill me with a great deal of confidence.

That’s right, there are plenty of ways to explain away travel sickness. But as of yet, there’s no 100 percent, medically-proven, definitive reason why some of us experience travel sickness and others do not. Even the N-H-bloody-S, the go-to font of medical knowledge in the UK, says it’s “thought to occur when…”. Real definitive.

It’s the Bermuda Triangle of illnesses. The Loch Ness of ailments. It might be there (maybe, kinda), but who knows why, how or whether we should just write it off as one of the greatest mysteries of our time.

So in honour of the evolutionary enigma that is travel sickness, let’s explore some of the top theories about why it happens.

From the idea that our bodies are in a constant state of turmoil because they wrongly think we’ve been poisoned to whether the condescending arses from my childhood were right and it really is a subconscious surfacing of some kind of Freudian fear we'll look at a range of explanations. Fingers crossed it isn't just be crappy genetics, and I’m eternally screwed and destined to walk everywhere...

The Sensory Conflict Theory

The most widely-believed explanation for travel sickness is that it’s based on something called sensory conflict theory. It’s the one the NHS refers to. The website reads:

Motion sickness is thought to occur when there's a conflict between what your eyes see and what your inner ears, which help with balance, sense.

Your brain holds details about where you are and how you're moving. It constantly updates this with information from your eyes and vestibular system. The vestibular system is a network of nerves, channels and fluids in your inner ear, which gives your brain a sense of motion and balance.

If there’s a mismatch of information between these two systems, your brain can't update your current status and the resulting confusion will lead to symptoms of motion sickness, such as nausea and vomiting.

So there you have it. It’s not rocket science. It’s that your senses are confused, so they tell you they’re confused by making you feel like crap. Basically.

Knowing that many experts believe this conflict exists makes some of the totally lame advice I’ve had about combatting travel sickness over the years a little less condescending. The suggestions that are often dealt out that attempt to address this conflict mainly involve concentrating on something else or looking forward to the horizon, as well as a whole host of others things to essentially trick your senses into thinking there’s no conflict. Or easing them into being okay with the conflict.

The Postural Stability Theory

Dr. Stoffregen, a professor of kinesiology, has a slightly more controversial theory. He doesn’t believe motion sickness is as inextricably linked to our inner ear as we think, but more to do with our posture. He thinks that some of us haven’t yet dealt with effective ways to maintain our posture, which brings on that awful swaying feeling, which brings on travel sickness.

A similar idea is explored by the negative reinforcement theory that looks at possible reasons for travel sickness as a means of evolving to be safer. It suggests that if we found ourselves in a situation where we weren’t moving normally, our bodies would make us feel bad to get us out of those situations, away from predators and in a safer environment:

If we assume that motion beyond the expected or that producing postural instability reduced evolutionary fitness, having a natural mechanism to avoid and terminate such motion would make sense.

So essentially our bodies are like, “Hey stop doing that awful thing because if you keep doing it something bad might happen.” Like if you hurt your leg and were hobbling around looking all weak and susceptible to attack, or were running really fast down a hill and didn’t already realise what a terrible idea that would be.

The Toxic Theory

Another popular theory is that some of us respond so terribly to being on a boat (or a car or a fairground ride) because our bodies think they’re being poisoned freak out to stop us from actually dying from these phantom toxins that aren’t really there.

Made famous by Dr. Michel Treisman, a psychologist at the University of Oxford in a piece of work called Motion Sickness: An Evolutionary Hypothesis, he suggests that motion sickness may have evolved as a way to cope with being poisoned. So if our bodies detect toxins, then the tell-tale signs, like dizziness, loss of coordination, and vomiting exist as a back-up plan. So we’ll throw up the toxins. This makes sense in that our bodies think we’ve been poisoned because we feel like we’re hallucinating. But we’re not. We’re just on a goddam boat, leading to movements that our bodies can't naturally replicate on two feet.

Anyone who has managed to play illness bingo with terrible food poisoning AND terrible travel sickness will probably be nodding their heads right now, as both feel really similar.

So there you have it, our bodies might just be huge drama queens who feel motion and panic that we’ve eaten some dodgy berries or we’ve been poisoned by some stupid frog.

Psychosomatic Causes

And obviously this is the one I hate the most. Just the mere hint at the fact I’m deliberately putting myself through this torture on some level doesn’t sit well with me. But, there is some science in it.

I spoke to therapist Michael Carthy, who specialises in helping people to overcome fears. (Full disclosure, Michael and I are engaged). Now he doesn’t deny people get travel sick, and that some people experience worse symptoms than others. But he does think we can make our symptoms worse.

“Sure travel sickness exists. But that doesn’t mean we don’t make it worse, a lot worse, with our negative thinking patterns. Worry that you’re not going to handle something, that you can’t get get through it, that you’ll fail or fall or throw up and you might actually be making it more likely to happen. We really can be our own worst enemies sometimes.”

It literally makes me wince to hear that. But at the same time I don’t doubt that, particularly in some situations, my experiences of throwing up, getting embarrassed and falling on people while travel sick probably isn’t doing my outlook and future health any favours. And this is from someone who actually feels okay about planes and travelling. Michael suggests that if you have a fear of heights or flying, your travel sickness might be worse as a physical response to that fear.

Links to Other Problems or Good Ol’ Genetics

Of course there’s a really good chance that travel sickness isn’t a thing on its own. But instead it’s a symptom of something else.

From a lot of research from medical professionals, as well as heaps of anecdotal evidence, it seems that people who have hormonal imbalances, women who are pregnant, those with type II diabetes, those with serious inner ear problems and those who experience migraines all find that travel sickness is worse when their other symptoms and conditions worsen.

It’s also worth mentioning that there might not really be a reason. Some of us might just have genes that make us more sensitive to some of the stuff already discussed above, like inner ear discrepancies or sensitive guts that wrongly think good food is poisonous.

Certainly, recent research from genetics company 23andMe would suggest that’s the case after finding the condition is heritable:

We’ve identified 35 genetic associations with motion sickness that fall into a few different biological categories. Some genetic variants are in or near genes involved in development, including development of the eye and ear. Other variants appear to be involved in neurological processes as well as glucose and insulin regulation.

So that still doesn’t explain why some of us have genes like that, but it does help us to understand the "how" a little more.

That’s All Really Interesting, But What Actually Is It?

Ah. Sorry. You didn’t think a feature built on shaky foundations about “evolutionary anomalies” would really tie up into a neat bow, did you?

The truth is, no one knows what it really is. It’s going to be one of life’s puzzles. Like the common cold and who really shot Kennedy, the reason some of us would rather throw ourselves off the edge of a boat than put up with the feeling of being on one remains something of a mystery.

Some of the theories I’ve outlined in this feature are generally considered water-tight. Maybe our senses just get confused because we’re overly sensitive, maybe we’re suffering from something else that makes us more prone to queasy feelings, or our bodies are just being little melodramatic crime fighters and are trying desperately to get rid of poison that isn’t there.

But there’s no medically-sound answer. And until there is we’ll all suffer our way through, just like Darwin. Because if he couldn’t figure it out, I don’t know if any of us can.

Image Credits: Carsickness, Woman Experiencing Motion Sickness, Abdominal Pain from Shutterstock