The famous Swiss developmental psychologist, Jean Piaget, believed that children begin to acquire the ability to reason between the ages of four and seven. Those who have taken a child development course will likely remember the conservation of matter experiment, where children younger than seven are not likely to understand that a beaker of water poured into a tall, thin container still contains the same amount of water, even though it might appear to be more.
A recent experiment suggests that children can reason a lot earlier than Piaget thought. In this March 2018 study published in the journal Science, researchers studied two groups of infants — those who were 12 months of age, and those who were 19 months of age. The learning of language and production of speech is just beginning around these ages, but is far from being mastered.
During the study, the children sat in their mothers’ laps and viewed distinct objects repeatedly. The moms were blindfolded so the babies could not pick up on any facial cues. Through animation, the children were first shown two objects, such as a dinosaur and a flower. The items were then hidden behind a black screen. In one experiment, the animation revealed a cup scooping up one of the objects — the dinosaur — which was then brought to the front of the screen. Half of the time, the barrier would then be removed to reveal, as expected, the remaining flower. In the rest of the instances, though, the screen was removed and a second dinosaur was revealed.
The results were the same for both age groups. Each child realized that something was not quite right in the second scenario, even though he or she was not able to articulate what was wrong. So how was this determined? Eye-tracking, a commonly used technique to gauge mental abilities in preverbal children, showed infants stared significantly longer at scenes where the unexpected object appeared behind the barrier, suggesting they were confused by the reveal.
Additionally, researchers reported infants’ pupils dilated when watching the animations that featured the illogical outcomes. Dilation of pupils is known to occur in adults working on logic problems and appears to provide more evidence that babies are aware of the way things “should” be.
It has long been believed that language underlies our ability to reason. Perhaps one of the reasons this is so is because most people would say the majority of their reasoning occurs through “talking to themselves.” However, this study suggests our capacity to reason logically may not actually depend totally on language. Babies who cannot yet speak can reason and make rational deductions. Says lead study author Nicoló Cesana-Arlotti, a postdoctoral fellow in the Department Psychological and Brain Sciences at Johns Hopkins University, “Our results indicate that the acquisition of logical vocabulary might not be the source of the most fundamental logical building blocks in the mind.”
Indeed, there are many parents out there who will confirm what this study suggests — their children are able to make logical deductions long before they can talk. Now we have scientific proof to back up this anecdotal evidence.
I find this study interesting, mainly because it demonstrates the fact that, at times, what we always thought as true might not in fact be the case. As studies often do, it raises more questions than answers. What about children who are nonverbal, such as those with autism or brain damage? Let’s not assume they can’t reason just because they can’t speak. What about those with cognitive disabilities? Perhaps studying their eyes as this study did could someday lead to a more accurate diagnosis and prognosis. The possibilities are many as more research into the mental development of young children continues.