Scientists Studied 113 Young Children and Found That Their Blinking May Reveal a Surprising Clue About How They Handle Change
A September 23 story from the New York Post brought attention to research examining whether the way young children blink could offer clues about their developing brains. The study, published September 15, 2026, in Communications Psychology, examined 113 children and found an association between spontaneous blinking and performance on a task requiring them to adapt to changing rules. The findings suggest that this seemingly ordinary movement may provide researchers with another way to study how children’s thinking skills develop.
However, the research is more specific than the idea that blinking reveals whether a toddler is well behaved. The scientists did not test whether children obeyed their parents, behaved politely, or avoided tantrums in everyday situations. Instead, they investigated cognitive flexibility, a mental skill that helps children adjust their responses when a situation demands something different.
What Executive Function Really Means
The research focused on executive function, a collection of mental abilities involved in managing thoughts, controlling impulses, remembering relevant information, and adjusting behavior toward a goal. These abilities help children respond when familiar rules change or when an immediate reaction needs to be reconsidered. They develop rapidly during early childhood and continue maturing as children grow.
Executive function is closely connected to self-regulation, but the two concepts are not interchangeable with being a well-behaved child. A youngster who struggles to switch between tasks is not necessarily disobedient, and a child who follows household rules does not automatically have stronger executive function in every situation. The study explored one measurable component of this development rather than offering a complete assessment of a child’s personality or behavior.
The Researchers Studied Children in Japan
The research team included scientists affiliated with the University of Tsukuba and Kyoto University in Japan. They recruited children from two preschools in Osaka and Kyoto, selecting participants who were between 35 and 80 months old. This age range covered children from nearly three years old through approximately six and a half, although the group is more accurately described as preschool-age children than toddlers alone.
A total of 113 children were included in the main analyses, with 55 girls and 58 boys recorded in the study. The researchers examined both performance on a cognitive task and activity in the prefrontal cortex, a region near the front of the brain involved in higher-level thinking. Their goal was to investigate whether individual differences in spontaneous blinking were associated with differences in cognitive flexibility and its underlying brain activity.
A Simple Card Game Became a Test of Thinking
To examine cognitive flexibility, the researchers used a task known as the Dimensional Change Card Sort. Children looked at cards that could be organized according to features such as color or shape, giving them a straightforward activity that required attention and rule-following. Although the game appeared simple, its changing instructions demanded that participants adjust their thinking rather than repeat the same response automatically.
The experiment included several stages in which children sorted cards according to different rules. Researchers recorded how accurately each child handled trials requiring a switch from one rule to another. This allowed the team to measure a specific mental skill using observable performance rather than relying exclusively on adults’ impressions of a child’s behavior.
The Rules Changed, and the Children Had to Adapt
During the task, children first sorted cards according to one feature and then moved to another, such as changing from color to shape. Later stages required them to alternate between the two rules, making it necessary to keep track of the current instruction. A child who continued following the previous rule after the switch would make an error even if the original rule had been understood correctly.
The researchers paid particular attention to success on trials that required a rule change. This measure helped distinguish simple familiarity with the game from the ability to adjust when the task changed. That distinction is important because cognitive flexibility involves responding appropriately to new demands, rather than merely repeating a learned action.
Researchers Measured Brain Activity and Blinking Together
The team used functional near-infrared spectroscopy, commonly abbreviated as fNIRS, to monitor activity in the children’s prefrontal cortex during the experiment. This noninvasive technique uses near-infrared light to measure changes related to blood oxygenation in tissue, giving researchers an indirect view of brain activity. It allowed them to investigate developing brain function without relying on more restrictive measurement methods that can be difficult to use with young children.
At the same time, a camera recorded each child’s face so the research team could count spontaneous eye blinks. The researchers did not tell the children that blinking was the focus of the experiment, helping them avoid deliberately changing the behavior being measured. According to the University of Tsukuba’s research announcement, the combination of video-based blink measurements and brain monitoring helped reveal a relationship between this everyday movement and cognitive performance.
The Scientists Counted Blinks From Video Recordings
The researchers calculated each child’s spontaneous eye-blink rate over a six-minute recording period while the child completed the task. Two trained raters independently counted blinks from the videos, and their measurements showed strong agreement. This method gave the team a practical way to quantify blinking without attaching specialized eye-monitoring equipment to the young participants.
Blink data were available for 112 children because one participant’s eyes could not be assessed adequately in the recording. The researchers calculated blink rate as the number of blinks per minute, making it possible to compare the measurements with performance on the card-sorting task. Importantly, the study examined naturally occurring blinking during a structured activity, not deliberate blinking or a parent’s subjective judgment of how often a child blinks.
More Frequent Blinking Was Associated With Better Rule-Switching
The main finding was that children with higher spontaneous eye-blink rates tended to perform better when the task required them to change rules. The relationship remained statistically significant after the researchers accounted for the children’s ages, suggesting that age alone did not explain the entire association. In other words, the result was not simply that older children blinked more and also performed better.
The association was not perfect, and the researchers did not find that blinking predicted every child’s performance with certainty. Some children who blinked more frequently performed well on the task, but that does not establish blinking as a reliable way to judge any individual child’s abilities. The finding instead points to a relationship across the group that deserves further investigation.
Age Was Important, but It Was Not the Whole Explanation
The study also found that spontaneous blinking generally increased across the early childhood period examined. The researchers observed relatively low blink rates and limited differences between children under four, while more pronounced individual differences appeared among older participants. Some children in the older part of the sample blinked more than 20 times per minute during the recording period.
Cognitive flexibility also improved with age, consistent with the rapid changes in executive function that occur during the preschool years. Yet the relationship between blinking and rule-switching accuracy remained after age was considered statistically. This raised the possibility that blink rate could eventually help scientists investigate developmental differences beyond what they can learn from a child’s age alone.
One Part of the Prefrontal Cortex Stood Out
The brain measurements revealed another important association involving the right dorsolateral prefrontal cortex. This region is part of the broader network involved in managing goals, resolving conflicting information, and adjusting responses when circumstances change. Children with higher blink rates showed greater task-related activation in this region, and activation there was also associated with better rule-switching performance.
The relationship was not equally apparent across every prefrontal region measured in the experiment. Instead, the association between blinking and brain activation was particularly evident in the right dorsolateral prefrontal cortex. The researchers interpreted this pattern as evidence that blinking may be related to the functional development of brain networks that support cognitive flexibility, rather than serving as a general indicator of every aspect of intelligence.
Why These Findings Could Matter Beyond a Card Game
Children encounter situations requiring flexible thinking throughout ordinary life, from adapting to new classroom instructions to changing plans during play. Executive function also supports skills involved in controlling immediate reactions, keeping relevant information in mind, and working toward a goal. Understanding how these abilities develop could help scientists build a more detailed picture of the mental processes that support learning and self-regulation.
The card-sorting experiment did not directly measure school achievement, friendship skills, family interactions, or children’s behavior during tantrums. Its relevance to those situations comes from the established role of executive function in everyday activities, not from direct evidence that children who blink more will behave better in every setting. The researchers’ findings therefore offer a possible clue about a developing cognitive ability, rather than a shortcut for predicting a child’s future success.
Dopamine May Help Explain the Connection
One possible explanation involves dopamine, a chemical messenger that contributes to communication between brain cells and plays a role in several cognitive processes. Previous research has linked spontaneous eye-blink rates to systems involving dopamine, which led the researchers to consider whether changes in these systems might help explain the association with executive function. However, blinking is influenced by multiple biological mechanisms, and it cannot be treated as a direct measurement of dopamine levels in a child’s brain.
The authors also discussed the possible involvement of other neurotransmitters and brain systems related to arousal. The precise mechanisms responsible for changes in spontaneous blink rate remain incompletely understood, including how much different chemical systems contribute to the behavior. Consequently, the study supports an association between blinking and cognitive development, not the conclusion that a higher blink rate proves a child has more dopamine or a more mature brain in every respect.
Earlier Research Also Explored Blinking and Self-Control
The broader connection between blinking and children’s cognitive processes did not begin with the 2026 study. In a 2024 study published in PLOS ONE, researchers examined children’s blink rates during a Jenga-like game in which an experimenter increasingly delayed taking their turn. That research explored how blinking varied with waiting time, parent-reported effortful control, and internalizing behaviors.
The findings suggested that the relationship between blinking and behavioral regulation can depend on the task and on individual differences among children. In a particular subgroup with high reported effortful control and low reported internalizing behaviors, blink rates decreased as the waiting periods grew longer. Rather than demonstrating a single universal pattern, this earlier work illustrates why scientists need to examine blinking in specific contexts before drawing conclusions about what it means.
The Study Has Important Limitations
Although the 2026 findings are promising, the research involved a particular age range and a group of children recruited from two preschools in Japan. The researchers measured performance on one established cognitive-flexibility task, so it remains uncertain whether the same relationship would appear across different tasks, age groups, and cultural settings. Independent studies with broader samples would help establish how consistently blink rate relates to executive function.
The study also did not follow the children over several years to determine whether their blink rates predicted later development. Because the researchers identified associations rather than experimentally changing blink rates, the results cannot establish that blinking causes better cognitive performance or that changes in executive function cause children to blink more often. The authors themselves called for further longitudinal research and independent verification to clarify the proposed developmental relationship.
Could Blinking Eventually Help Researchers Study Brain Development?
One attractive feature of the approach is that spontaneous blinking can be measured from ordinary video recordings. Researchers may therefore be able to collect blink-rate data in settings where more complicated monitoring equipment would be impractical, provided that recordings and measurements meet appropriate research standards. Automated video analysis could also make it easier to process large numbers of recordings, although such applications would require validation.
The prospect is particularly interesting because studying brain development in very young children can present practical challenges. A simple, noninvasive measurement associated with executive function could give researchers another tool to compare developmental patterns and investigate how cognitive skills emerge. Before it becomes an established assessment method, however, scientists will need to determine how reliable it is across different environments and how much useful information it adds beyond existing developmental measures.
What Parents Should Take Away From the Findings
For parents, the most important distinction is that a child’s blink rate is not a test of obedience, good manners, or parenting quality. The research did not show that children who blink more often have fewer tantrums, listen more consistently, or handle every difficult situation better than their peers. It identified a statistical relationship between a physiological behavior and performance on a particular task involving changing rules.
The findings nevertheless offer an intriguing look at how an everyday movement might reflect processes taking place during early brain development. As researchers continue investigating the connection, spontaneous blinking could become one useful piece of a larger picture of children’s emerging cognitive abilities. For now, the study’s most meaningful discovery is not a new way to identify a perfectly behaved toddler, but a potential clue to how young children’s brains learn to adjust when the rules change.
