Kids as young as 4 innately use sorting algorithms to solve problems

Research indicates that children as young as four can effectively devise solutions to challenging problems, exemplified by their ability to create sorting algorithms similar to those used in computer science. This new perspective suggests that such cognitive skills develop considerably earlier than previously understood, prompting a reevaluation of established theories in developmental psychology.

Classic studies by Swiss psychologist Jean Piaget, made famous in the 1960s, assessed children’s ability to sort sticks by length—a task Piaget termed “seriation.” These investigations concluded that children lacked structured problem-solving strategies until around the age of seven, instead relying on trial and error in chaotic attempts.

However, recent work from Huiwen Alex Yang and colleagues at the University of California, Berkeley, reveals that even a small fraction of four-year-olds can formulate algorithmic solutions for similar tasks, with over a quarter of five-year-olds demonstrating the same capability.

“Perhaps we have underestimated children’s potential,” states Yang. “We must delve deeper into their reasoning abilities and the strategies they employ.”

In their experiments, researchers engaged 123 preschoolers through early adolescents (ages 4 to 9) in sorting digital representations of bunnies by height. Initially, they could visually assess and compare the heights, allowing all participants to sort with ease.

As the challenges intensified, with the heights hidden from view, children were required to select two bunnies at a time to compare. After viewing the pair, the children learned whether they were in the correct order; incorrect pairs triggered automatic switching. This adjustment necessitated the development of fresh strategies for sorting without a holistic view of the group.

The team sought to identify whether children were utilizing known algorithms by examining their sequences of comparisons. Results indicated that children’s performance was significantly above random chance; notably, they independently identified at least two sorting methodologies recognized in computer science: selection sort and cocktail shaker sort.

In 34 percent of trials, children exhibited sequences suggesting they applied recognized algorithms. Out of 667 trials, children employed selection sort in 110 instances and cocktail shaker sort in 141 instances, with 21 tests showcasing a mix of both strategies. A distinct count of 67 out of 123 children employed at least one identifiable algorithm, and 30 children utilized diverse strategies at different times during the study.

Age was reportedly correlated with algorithm usage; only 2.9 percent of four-year-olds demonstrated identifiable algorithms, contrasting sharply with 25.5 percent of five-year-olds and 30.7 percent for six-year-olds. By nine years of age, more than 54 percent of participants employed recognizable algorithms.

“The history of challenging Piaget’s conclusions is long,” remarks Andrew Bremner, from the University of Birmingham. While he reveres Piaget as a revolutionary figure whose insights into developmental psychology shaped our understanding of growth stages, he acknowledges Piaget’s limitations in experimental design. “It has been repeatedly demonstrated that children can achieve tasks Piaget attributed to older ages.”

Gradually, contemporary research reaffirms Piaget’s foundational theories while suggesting a more optimistic timeline for developmental milestones. This latest study notably contributes to the investigation of seriation—a process historically resistant to contrary evidence of children’s capabilities at younger ages.

“Children succeed at this task in contexts where we previously underestimated them,” notes Bremner, emphasizing their use of strategic thinking rather than perceiving the world as a blank slate.

According to Sam Wass from the University of East London, Piaget postulated that gaining a thorough comprehension of complex systems was necessary before children could forge strategies. However, this view is increasingly challenged.

“This study reflects a broader movement within psychology that contests the notion that complex behaviors necessitate intricate underlying thoughts,” asserts Wass. “As shown by this research, children can manifest seemingly sophisticated behaviors stemming from a simpler set of rules.”