Every day, millions of people do things they never imagined they could tolerate. They change diapers, clean messes, wipe noses, and handle substances most humans instinctively recoil from. The immediate reaction is familiar and visceral: a tightening stomach, a sharp urge to turn away, a deep internal “yuck.” This feeling, known as disgust, is one of the brain’s oldest warning systems. It exists to protect us.
But what happens when avoidance is no longer an option? When exposure is constant, unavoidable, and lasts for months or years?
New research from neuroscientists at the University of Bristol suggests that the brain does not simply endure disgust. It adapts. Over time, and under the right conditions, it quietly rewires itself.
Disgust as a Guardian, Not a Quirk
Disgust is often misunderstood as fussiness or squeamishness, but as Dr. Edwin Dalmaijer, a cognitive neuroscientist involved in the study, explains, it is anything but trivial. Disgust is a basic human emotion designed to keep us safe from harm. It pushes us away from spoiled food, dirty environments, and bodily fluids that could carry disease.
When disgust strikes, the body reacts automatically. Nausea rises. Muscles tense. The urge to withdraw is immediate and powerful. These reactions evolved to work fast, long before conscious thought could step in.
Yet for years, scientists have debated whether this deeply ingrained response can truly change. Does repeated exposure dull disgust, or does the brain simply endure it again and again?
Parenthood as a Natural Experiment
To answer that question, the researchers turned to a life transition that forces prolonged exposure to unpleasant substances without offering an easy escape: parenthood.
Parents cannot opt out of caregiving based on discomfort. From the moment a child arrives, exposure increases dramatically. Dirty nappies, vomit, mucus, and other bodily effluvia become part of daily life. Importantly, this exposure unfolds naturally over time, making parenthood an ideal real-world setting to observe how disgust might shift.
The study, published in the Scandinavian Journal of Psychology, compared 99 parents and 50 non-parents, using questionnaires and behavioral measures. Participants were shown child-related stimuli, including images of soiled nappies, and researchers carefully observed reactions such as how much people looked away.
The goal was not just to ask people how they felt, but to watch how their bodies responded.
A Clear Divide in Reactions
The difference between parents and non-parents was immediately visible. Non-parents showed strong avoidance when confronted with images depicting bodily waste. Their gaze shifted away quickly, reflecting the classic disgust response.
Parents, however, told a more complicated story.
Those whose children had begun eating solid food, whether recently or long ago, reacted very differently. They showed little to no behavioral avoidance of soiled diapers. Even more strikingly, their reduced disgust response extended beyond child-related messes to general bodily waste.
This was not simple tolerance in the moment. It looked like genuine desensitization, a reshaping of emotional responses that had settled in over time.
The Surprising Power of Early Infancy
Yet the findings held an unexpected twist.
Parents whose youngest children were still exclusively milk-fed reacted much like non-parents. They showed strong disgust avoidance, even if they had older children and past caregiving experience. The presence of a very young infant appeared to keep disgust responses heightened.
This pattern surprised the researchers. If repeated exposure alone reduced disgust, then any parent with experience should show desensitization. Instead, the brain seemed to follow a timeline, easing its defenses only after a certain developmental stage had passed.
A Brain Tuned to Protect the Vulnerable
The researchers believe this shift reflects an evolutionary adaptive response. During the earliest stage of infancy, babies are particularly vulnerable to illness. Heightened disgust during this time may help parents avoid bringing harmful substances close to their infants.
As children grow and their immune systems strengthen, the balance shifts. Parents are increasingly exposed to bodily waste through weaning and illness, and avoidance becomes impractical. At this stage, long-term exposure appears to gradually “turn down” the disgust response, allowing caregiving to continue without constant emotional distress.
Dr. Dalmaijer describes this process vividly. Parents are “bombarded with grossness from day one,” yet after the sensitive early months, continuous exposure seems to inoculate them against disgust.
The brain, faced with an unchangeable reality, adapts.
Disgust That Fades, and Stays Faded
One of the most important findings is that reduced disgust did not remain limited to childcare situations. Parents who showed desensitization reacted less strongly to other forms of bodily waste as well. This suggests that caregiving can fundamentally reshape how disgust operates across contexts.
Disgust is often described as a stubborn emotion, difficult to alter even with repeated exposure. Yet this study provides strong evidence that long-term, unavoidable exposure can change it in lasting ways.
Parenthood does not just alter schedules and priorities. It appears to recalibrate emotional responses at a deep level, influencing how the brain interprets sensory information long after diapers are gone.
Beyond the Family Home
While the study focused on parents, its implications stretch much further. Many professions require regular contact with unpleasant substances. Nursing care, sanitation work, elder care, and medical support roles all involve managing disgust on a daily basis.
These jobs are often difficult to staff and retain, in part because the emotional burden of repeated exposure can be overwhelming. Understanding how disgust changes, and when it remains strongest, could help develop better support strategies for people in these roles.
By revealing that disgust can be reshaped through long-term exposure, but may remain heightened during periods of vulnerability, the research offers insight into how emotional training and workplace support might be structured more effectively.
Why This Research Matters
This study matters because it shows that the human brain is not locked into its emotional reactions. Even deeply rooted responses like disgust, designed to protect us from danger, can be modified by life experience.
The findings reveal a delicate balance between protection and adaptability. Disgust stays strong when it is most needed, guarding vulnerable infants from harm. Later, when caregiving demands increase and avoidance becomes impossible, the brain gradually eases its response, allowing parents to function without constant distress.
In doing so, the research challenges the idea that emotions like disgust are fixed. It shows that caregiving does not just require patience and resilience. It actively reshapes how humans experience the world.
Understanding this process has the potential to improve support for caregivers everywhere, from parents at home to professionals on the front lines of care. It reminds us that behind every routine act of caregiving, the brain is quietly adapting, learning when to recoil and when to stay present.
And in that adaptation lies a powerful testament to the flexibility of the human mind.
Study Details
Yifan Huang et al, Parents Develop Long‐Term Disgust Habituation, but Only After Beginning to Wean Their Children, Scandinavian Journal of Psychology (2026). DOI: 10.1111/sjop.70069
