Parabolic flights are famous for creating short bursts of weightlessness, but the most striking result in this study was psychological. Among 24 novice male participants, the men who adapted best to the violent sequence of climbs, drops and changing gravity were more likely to score high on boredom susceptibility, a trait tied to impatience with routine and monotony. They also had a much lower history of motion sickness. The pattern is surprising because thrill seeking alone did not separate the groups. A narrower human tendency, dislike of repetition, did.
A 2018 study in Frontiers in Psychology found that the seven men placed in the adaptive group scored higher on boredom susceptibility than the 15 men placed in the maladaptive group, while also scoring lower on the Motion Sickness Susceptibility Questionnaire. The paper, Sensation Seeking and Adaptation in Parabonauts, argues that both traits may help identify who is more likely to stay functional during the physical strain of a zero-g flight.
Researchers did not present boredom as a magic shield and they did not claim that one personality score can decide who belongs in the cabin. Their finding was narrower and more useful: some people arrive with a mix of habits and sensitivities that seems better suited to an environment where the body keeps getting signals that do not match normal life. For future commercial passengers and for research teams that rely on first-time fliers, the result raises a practical question about how much adaptation depends on the inner style a person brings aboard before the aircraft even leaves the runway.
How the team sorted adaptive and maladaptive fliers
The work came from the ETAP-0g Project, supported by CNES and the Region Lorraine and it used data collected during two flight campaigns between 2010 and 2011. All participants were healthy men with no previous parabolic flight experience, no severe motion sickness history and no major psychiatric, neurological, or vestibular disorders. During the flights they carried out the same simple reaction-time tasks and none used anti-emetic drugs before or during the campaign.
Out of 24 volunteers, the final analysis used 22 after two participants were removed because they could not complete the required reaction-time tasks. The researchers then divided the remaining men into an adaptive group of seven and a maladaptive group of 15. They did not rely on vomiting alone. Grouping depended on the presence or absence of motion sickness signs during flight, which gave the team a broader picture of adaptation than a single dramatic symptom would provide.
After the flights, the participants completed several questionnaires. One measured sensation seeking through Zuckerman’s Sensation Seeking Scale. Another measured usual coping style through Brief COPE. A third measured motion sickness history through the short form MSSQ. Readers who want the indexed study record can also find it in PubMed, which summarizes the same main outcome: better-adapting fliers looked less vulnerable to motion sickness and more intolerant of routine.
Why boredom susceptibility may help in zero g
Boredom susceptibility sounds trivial until it is placed inside an environment built around abrupt sensory conflict. In the study, this trait did more than color personality. It was the only sensation-seeking subscale that clearly separated the two groups. The adaptive participants were not simply bigger fans of danger in every form. They stood out because they disliked sameness and were more likely to seek novelty and change.
The authors connected that result to a possible behavioral advantage. A person who often looks for new experiences may arrive with more practice at handling novelty, uncertainty and sensory disruption. The paper used careful language, but the idea is plain enough for general readers: repeated exposure to new situations may leave some people more flexible when gravity itself starts changing under their feet. The authors also quoted earlier work on parabonaut personality, including a 2014 study in Aviation, Space and Environmental Medicine, which described people attracted to parabolic flight as more stimulation-seeking and emotionally stable than the general population.
The study’s most concise summary came from the abstract itself: “These characteristics may have contributed to developing a certain degree of flexibility.” That is a modest claim and it is the right size for the evidence. The authors were pointing to a plausible psychological route, not proving a direct cause. Another related paper from the same research line, published in 2017 in Acta Astronautica, found that mood states also differed between better and worse adapters before and during parabolic flights, which supports the broader idea that adaptation is partly behavioral and not just mechanical.
Motion sickness history still carried heavy weight
The cleaner numerical separator was motion sickness history. The adaptive group had a median childhood MSSQ score of 0.00, compared with 5.63 in the maladaptive group. In adulthood the adaptive median was also 0.00, compared with 1.29 in the maladaptive group. For the total MSSQ score, the adaptive group had 1.00 while the maladaptive group had 6.75. Those are not tiny differences at the margins. They describe two groups that entered the flight with very different backgrounds in how their bodies had handled movement before.
When the researchers built their logistic regression model, they used two inputs: the total motion sickness score and boredom susceptibility. Together those measures gave 93.33 percent correct classification for people labeled “not successfully adapted.” That result explains the numerical hook in this story. It also deserves restraint. High classification accuracy inside a small exploratory sample can reveal a strong signal, but it can also look more stable than it really is until larger studies test the same pattern again.
The motion sickness side of the result also fits a longer scientific record. The questionnaire used here was based on John Golding’s revised MSSQ paper from 1998, available through Brain Research Bulletin. A later parabolic-flight study by Golding and colleagues, published in 2017 in Aerospace Medicine and Human Performance, reported that people who vomited during zero-g flights had higher MSSQ scores, even though vomiting by itself was an imperfect predictor. The 2018 Frontiers paper pushed the issue further by treating adaptation as a wider cluster of symptoms instead of a yes-or-no vomiting outcome.
What weightlessness does to judgment and comfort
A parabolic flight is a harsh short-form test of human adaptation. An aircraft climbs steeply, enters free fall and gives passengers about 20 seconds of microgravity before pulling out and loading the body again. The inner ear, the eyes and the rest of the body can stop agreeing about motion. That mismatch is one of the main reasons people feel dizzy, sweaty, sleepy, nauseated, or disoriented. Space agencies and clinicians have described the same broad problem for decades and a classic review by Lackner and DiZio laid out how space motion sickness grows from conflicting sensory signals rather than from weakness or poor will.
Inside that setting, personality can affect what a person does with stress once the body starts sending unstable messages. Some people become rigid and look harder for control through advice or problem-focused planning. Others may stay looser and accept the unfamiliar environment more quickly. The 2018 paper found only a trend, not a significant difference, for instrumental support seeking, so any strong claim would go beyond the data. Even so, the behavioral picture remains coherent: better-adapting fliers combined lower motion sickness susceptibility with a stronger taste for novelty.
Commercial spaceflight companies care about this kind of evidence because a cabin full of first-time passengers is very different from a professional astronaut corps. Screening cannot erase discomfort and the paper does not suggest a final passenger-selection tool. It does suggest that preflight preparation could improve if trainers look beyond medical clearance alone. People who know they are sensitive to motion, or who struggle when routines break, may need different coaching, closer monitoring, or both.
What this study can support and what it cannot
The study was exploratory, all participants were men and the final model rested on 22 analyzed cases. Those limits are large enough that every broad conclusion needs to stay provisional. The authors said so directly. They called for larger samples, better tools for grading adaptation difficulty and follow-up work that separates state coping from motivation while also checking prior flight adaptation and gender. A later commentary on the paper, posted in 2024 in Frontiers in Psychology, placed the study inside a wider conversation about personality profiling for extreme environments.
Even with those cautions, the result remains useful because it avoids a simplistic story about fearlessness. The men who adapted best were not defined by one broad heroic trait. They appeared to combine lower susceptibility to motion sickness with a specific form of novelty-seeking that resists repetition and routine. That combination points to a practical lesson for future research in aerospace medicine: the people who perform well in microgravity analogs may be the ones whose daily behavior already leans toward change, variety and quick adjustment.
For readers outside the space world, the deeper point is about human behavior under unusual physical stress. Bodies react to sensory conflict, but minds also bring habits into the struggle. Some people enter a turbulent environment already prepared to improvise, to tolerate the strange and to keep moving when the normal rhythm disappears. In a plane that briefly becomes a zero-g lab, that small psychological edge may be enough to separate discomfort from functional adaptation.
