Scientists have uncovered a powerful illusion in how we remember the timing of repeated events, showing that the more often something is repeated, the further in the past its first occurrence feels—even when that’s not actually the case. This phenomenon, documented in a recent study published in Psychological Science, may have far-reaching repercussions for how we piece together our personal memories, judge news events, and even recall everyday experiences—significant insights for a society like Thailand’s, where repetition in news, advertising, and education is common.
Many Thais often experience the sensation that frequently repeated headlines, advertisements, or lessons have been a part of their lives for much longer than the calendar suggests. The new research, conducted by cognitive scientists led by an assistant professor at The Ohio State University and a researcher at another US institution, shows that this is not just a casual feeling but a measurable illusion, called the “temporal repetition effect.” Essentially, repetition makes us remember something as happening earlier than it really did—sometimes distorting our perception by as much as 25 percent. This finding challenges the prevailing psychological assumption that stronger, clearer memories appear more recent in our minds.
The team ran six experiments involving hundreds of adult participants, exposing them to repeated and non-repeated images and then asking them to recall the timing of each image’s first appearance. Intriguingly, individuals consistently recalled the first instance of a repeated image as further in the past compared to an equally old but non-repeated image. Repetition, it turned out, was a powerful driver of this “time illusion.” The distortion grew larger the more times the image was repeated: viewing an object five times, for example, made its original appearance feel even more distant, a pattern that held across all experimental variations (PsyPost).
What makes this effect even more compelling is its independence from deliberate reasoning or strategy. Survey responses indicated that most participants were unaware that repetition influenced their judgments about timing. Even when directly warned in advance to focus on when they encountered an image for the first time, people remained susceptible to the illusion. Whether there were pauses between image-viewing sessions or not, the tendency to misplace the timing of repeated images persisted.
In one twist on the design, participants who were simply shown two images—one repeated and one not—and asked which had come first, wrongly chose the repeated image as appearing earlier about 80 percent of the time, even in cases where it had always come after the non-repeated one. A final experiment confirmed that the effect holds over days and not just within minutes, suggesting the “time illusion” lingers and may shape our recall of news cycles, work routines, or school lessons weeks after the fact.
The study’s authors theorize that with each repetition, later exposures cue strong reminders of the first, giving the brain an impression that the original event was further ago. Alternatively, memory for timing may not be stored directly, but reconstructed based on contextual hints like repetition. This could explain why repeated government messages, media stories, or common phrases in Thailand’s classrooms and advertisements often feel almost timeless—even if they’re fairly new.
Expert opinion has echoed the relevance of these findings. According to the lead author, “time perception is illusory. Our sense of when things occurred is systematically distorted in predictable ways. These distortions can be substantial, even if their causes are simple, like the mere repetition of information.” This goes against standard psychological models, which generally assume that fresher, clearer memories—made vivid through repetition—should feel more recent, not more distant.
Although this research was carried out with adults in the United States, its core implication—that repetition warps our mental calendar—likely transcends cultural boundaries. For Thailand, where teachers repeat core lessons, news gets recycled, and product campaigns saturate daily routines, the temporal repetition effect could affect everything from how students recall exam content, to the way citizens follow news stories, to the memory of political events and public health campaigns. For example, frequent public health messaging about dengue fever or COVID-19, repeated across multiple media outlets, might make the initial outbreak feel much further in the past than it actually is—a psychological blind spot with clear social implications.
Historically, Thai society has placed great value on rote learning and repetition as tools for education and social order, from Buddhist chanting in temples to routine slogans in public campaigns. This cultural context makes the “time illusion” especially relevant. A teacher at a prominent Bangkok school points out that older students often remember details of lessons but are confused about timelines: “We repeat lessons before every exam, but many students feel as if we studied that topic years ago. This research gives us insight into why that happens.”
Looking forward, this discovery opens up numerous questions: Would the effect operate differently for emotionally charged or traumatic events, such as natural disasters, or during periods of political upheaval? Could the illusion vary in children, elders, or those with memory disorders—key groups in Thailand’s rapidly aging society? The researchers themselves recommend further study, particularly in non-Western cultures, other age groups, and with different types of memory—social, emotional, or collective.
For Thai readers and policy-makers, the main takeaway is clear: our sense of when something happened can easily be tricked. Whether you’re a student preparing for university entrance tests, a company planning advertising strategies, or a government agency managing public memory of events, understanding this temporal illusion is critical. Practical steps could include deliberately timestamping key pieces of information in educational materials, news broadcasts, and public health messages to counteract this psychological distortion. Families and individuals, too, might keep diaries or use smartphone reminders to clarify the sequence of repeated activities or experiences.
Ultimately, as the study author puts it, “We really want to know what other factors influence how our mental timelines are shaped by our experience.” For Thailand, embracing this knowledge could foster more accurate collective memory, enhance education, and inform how we process the relentless repetition in modern life—a valuable lesson as society grows ever more saturated with repeated information.
Read more in the original report at PsyPost and in the journal Psychological Science.