"Rearrange the Invisible Rabbits": The Surprising Logical Skills Demonstrated by a 4-Year-Old - The Moment Play Turns into Learning

1. What is "Surprising"?

The German newspaper HNA, in its October 9, 2025 edition, introduced the latest findings on the cognitive abilities of young children in an article titled "4-Year-Olds Are Smarter Than We Thought." The article points out that Piaget's theory, which has been the foundation of educational and developmental psychology for nearly 60 years—suggesting that systematic problem-solving is difficult until at least age 7—is being reconsidered. It cites an explanation from the family-oriented media Hallo:Eltern and conveys the essence of the research. hna.de

2. The Experiment's Key: Rearranging "Invisible Heights"

According to a summary by Hallo:Eltern, a team from UC Berkeley conducted a PC game-style task with 123 children aged 4 to 10. The children could not directly see the "rabbits' heights" and had to rearrange them in order of height using only information about their "shoes" as clues. The task was designed to be unsolvable by mere guesswork, requiring logical reasoning (which two figures to swap to improve order) and procedural planning. hallo-eltern.de

As a result, more than half of the children independently discovered a "procedure" to efficiently organize the order while scrutinizing the information. The strategies they used corresponded to "selection sort" and "shaker sort" known in computer science, as reported.

3. Even 4-Year-Olds Spontaneously Use "Algorithmic Thinking"

The primary source of this study is the article "Children spontaneously discover efficient solutions to a difficult sorting task" published in Nature Human Behaviour, which is also listed with a DOI in the Kidd Lab's publication list. This means it is a peer-reviewed study accepted by a journal.

In a research explanation (distributed by The Conversation and reprinted by various outlets), it is clearly stated that "more than half of the participating children demonstrated structured algorithmic thinking, even observable at age 4." This contradicts the classical view that systematic strategies are developed before Piaget's "concrete operational stage" (around age 7). Importantly, the task was designed to be unsolvable through "direct observation," making random trial and error ineffective.

4. The Significance of the Study: Was Piaget Wrong?

Piaget was not "wrong." Many of his observational discoveries still hold in educational settings. However, this study highlights that young children can switch to reasoning and spontaneously generate strategies depending on "task design." In other words, young children's thinking is context-dependent, and with the right presentation of information and rule design, they can achieve surprisingly advanced "proceduralization."

Considering this "context dependency," the question in practice shifts from "When should abstract concepts be taught?" to "What kind of task design encourages young children to naturally discover strategies?" Kidd and colleagues' work is significant in showing the "key to design."

5. What Can Be Achieved?—Practical Points for Education and Family

• Incorporate "Logical Friction" into Play: Incorporating games that require filling in unseen information through reasoning (such as rules on the back of cards or conditional swaps) naturally shifts play from mere trial and error to "thoughtful play." This is the essence of the research task. hallo-eltern.de

• Visualize Procedures: Externalizing sorting procedures with words, arrows, or blocks makes it easier for children to reflect on their strategies.

• Adults Provide "Information," Not "Answers": Provide only the basis for comparison (clues) on which swaps improve order, leaving the solution to the child.

• A Realistic Solution to the "Too Early for STEM" Issue: Instead of early learning of abstract symbols, it is crucial to provide "playgrounds" that expose children to abstract structures (order, conditions, repetition), as suggested by explanations via The Conversation.

6. Reactions on Social Media: Polarization Between Welcome and Caution

Welcoming Side

• The official account of the academic journal also summarized it as "Young children spontaneously discover efficient sorting," making it a topic of discussion. The study's reliability (peer-reviewed journal acceptance) and "spontaneity" are focal points.

• On Facebook's The Conversation post, comments included voices saying "We have underestimated children" and proposals to rethink play design.

• On Reddit, multiple threads spread the introduction of "4-year-olds discovering sorting strategies," sparking ideas for play at home.

Cautious Side

• There are also a significant number of voices warning against the "overheating of early education." It is pointed out that we should avoid confusing "some children can" with "expecting it from everyone." In discussions around the education community, the difference between expectation and pressure is repeatedly mentioned.

Supplement from Researchers and Commentators

• The methodology is designed so that "invisible information" prevents progress by chance. Posts repeatedly emphasize that the task's characteristics drew out children's reasoning, as explained in reprinted articles (such as SeattlePI).

7. Three Premises to Avoid Misunderstanding

1. Not Everyone Progresses at the Same Pace: Age only indicates the "lower limit of potential." In reality, the use of algorithmic strategies increased with age.

2. Generalizing "Smartness" is Prohibited: Discovering strategies in this task does not equate to development in other areas such as language or social skills.

3. "Task Design" is the Main Actor: If the conditions for children to switch to logic are met, the results change dramatically. Conversely, if the design is poor, it becomes "just trial and error."

8. Checklist for Practical Application (For Childcare and Home)

• Explicit Repeatable Rules (e.g., swaps are only allowed for "incorrectly ordered pairs")

• Feedback is Binary (Improves/Doesn't Change). Minimize Redundant Explanations

• Record Procedures (using arrow cards or order notes) to visualize "procedures"

• Intentionally Create "Invisible Information" (covers, back-side rules)

• Praise "Improvement Moves" Over Winning (local improvements are the core of strategy discovery)

9. Position and Connection of the Research

Past achievements of the Kidd Lab include studies on children's attention and learning "just rightness (Goldilocks effect)" and reactions to inaccurate information, addressing the relationship between environment and learning strategies. This work elegantly demonstrates that "appropriate stimulus design can draw out advanced reasoning in young children" in the context of that research.

10. Conclusion: Do Not Bind Children with "Preconceptions"

The key point of this study is the demonstration that "young children have a 'logic switch'." Whether the switch is flipped depends on the task design by us adults.Materials given under the assumption of inability can put children's potential to sleep.Refining information design under the assumption of ability—this is the update here and now.