On any road trip, there’s usually a clear divide. Someone in the back seat is scrolling their phone or reading a book without a second thought, while someone else can’t even glance down at a map for more than a few seconds before feeling queasy. Both are sitting in the exact same moving car, yet their bodies are having completely different experiences.
Motion sickness isn’t just a matter of a “weak stomach.” It comes down to how your brain processes conflicting signals about movement, and genetics plays a real role in how prone you are to that conflict in the first place.
What Causes Motion Sickness
The leading explanation for motion sickness is called sensory conflict theory. Your brain constantly combines information from your eyes, your inner ear’s balance system, and receptors throughout your body to build a sense of where you are and how you’re moving. In a moving car, your inner ear senses the motion of the vehicle, but if your eyes are focused on something stationary relative to you, like a book or a phone, your visual system reports that you aren’t moving at all. That mismatch between what your inner ear feels and what your eyes report appears to be what triggers the nausea, dizziness, and general discomfort of motion sickness.
A large genetic study conducted through 23andMe identified dozens of specific genetic locations associated with motion sickness susceptibility, including genes involved in inner ear development, balance, and even blood sugar regulation. This wide range of genetic involvement helps explain why motion sickness seems to draw on several overlapping body systems rather than a single, isolated cause.
Why Reading Specifically Tends to Be a Trigger
Reading is one of the more reliable motion sickness triggers precisely because it requires your eyes to stay fixed on something that isn’t moving with the vehicle, maximizing the mismatch between your visual and inner ear signals. This is part of why looking out at the horizon, which at least gives your eyes some visual confirmation of movement, tends to reduce symptoms for many people, while looking down at a stationary page tends to make them worse.
How Common Is Motion Sickness
Motion sickness is extremely common, with research suggesting a substantial share of the population experiences it at some point, and susceptibility varies widely from person to person. Some people are highly prone to it in almost any moving vehicle, while others rarely or never experience it, even in situations like boats or turbulent flights that reliably affect most people to some degree.
Does Motion Sickness Affect Your Health
Motion sickness itself isn’t dangerous, though it can be genuinely unpleasant and disruptive, particularly for people who experience it frequently during travel or commuting. In rare cases, chronic or unusually severe motion sickness symptoms can overlap with underlying inner ear or balance disorders, so if symptoms seem unusually intense, persistent, or unrelated to actual motion, it’s worth mentioning to a doctor to rule out anything beyond typical motion sickness.
What Motion Sickness Genetics Means for You
If you’ve spent years assuming you just need to “get used to” reading in the car while everyone else seems to manage it fine, your genetics may be working against you in a way that practice alone won’t fully solve. Understanding your inner ear and sensory processing genetics can help explain a pattern that’s likely followed you since childhood.
A home DNA test with a detailed sensory traits report can offer insight into your specific motion sickness susceptibility, which can be genuinely useful for planning travel, choosing seating, or simply understanding why some trips are harder on your body than others.
Frequently Asked Questions
Can You Reduce Motion Sickness Even if You’re Genetically Prone to It?
Yes. Looking at the horizon instead of close objects, sitting in the front seat or over the wing of a plane, and getting fresh air can all reduce symptoms, even for people with a strong genetic tendency toward motion sickness.
Do Motion Sickness Medications Actually Work?
Many over-the-counter and prescription options can reduce symptoms effectively for most people, though individual response varies, and it’s worth discussing options with a pharmacist or doctor if motion sickness significantly affects your travel.
Does Motion Sickness Get Better or Worse With Age?
Susceptibility often peaks in childhood and tends to decrease somewhat in adulthood for many people, though this pattern varies quite a bit and some people remain highly susceptible throughout life.
Is Motion Sickness Related to Migraines?
There does appear to be some overlap. People who experience migraines report higher rates of motion sickness than the general population, suggesting a possible shared sensitivity in how the brain processes certain sensory signals.
So the next time you’re stuck in the back seat feeling queasy while everyone else scrolls through their phone without a care, know that your inner ear and your eyes are simply disagreeing more dramatically than theirs are.