Children’s exploratory play tracks the discriminability of hypotheses

Effective curiosity-driven learning requires recognizing that the value of evidence for testing hypotheses depends on what other hypotheses are under consideration. Do we intuitively represent the discriminability of hypotheses? Here we show children alternative hypotheses for the contents of a box and then shake the box (or allow children to shake it themselves) so they can hear the sound of the contents. We find that children are able to compare the evidence they hear with imagined evidence they do not hear but might have heard under alternative hypotheses. Children (N = 160; mean: 5 years and 4 months) prefer easier discriminations (Experiments 1-3) and explore longer given harder ones (Experiments 4-7). Across 16 contrasts, children’s exploration time quantitatively tracks the discriminability of heard evidence from an unheard alternative. The results are consistent with the idea that children have an “intuitive psychophysics”: children represent their own perceptual abilities and explore longer when hypotheses are harder to distinguish.

“Wow, I did it!”: Unexpected success increases preschoolers’ exploratory play on a later task

Exploratory play supports children’s learning, but the factors that influence play are not fully identified. Here, we investigate whether experiencing an unexpected success on an initial task influences children’s exploration on a subsequent task. In Experiment 1 (N=72), we found that when 4-year-olds successfully completed a puzzle that they were told is hard (compared to when they were told that the puzzle is easy or at baseline when no difficulty information was provided), they spent more time exploring and attempted more different interventions with a subsequent novel toy. This suggests that an unexpected success influences children’s subsequent exploration. In Experiment 2 (N=48) we examined two alternative interpretations of the Experiment 1 findings: that children carried over difficulty assumptions from task 1 to the new toy or that children had unused attentional resources. Children completed the puzzle and then were told that the novel toy itself was either easy or hard. Children did not explore longer or more variably across these conditions, providing evidence against these alternative accounts. Our findings point to an important role for past playful experiences: unexpected success on one task motivates children to explore longer and with more breadth on another task.

Exploratory play, rational action, and efficient search

Play is a universal behavior widely held to be critical for learning and development. Recent studies suggest children’s exploratory play is consistent with formal accounts of learning. This “play as rational exploration” view suggests that children’s play is sensitive to costs, rewards, and expected information gain. By contrast, here we suggest that a defining feature of human play is that children subvert normal utility functions in play, setting up problems where they incur needless costs to achieve arbitrary rewards. Across four studies, we show that 4-5-year-old children not only infer playful behavior from observed violations of rational action (Experiment 1), but themselves take on unnecessary costs and perform inefficient actions during play, despite understanding and valuing efficiency in non-playful, instrumental contexts (Experiment 2-4). We end with a discussion of the value of apparently utility-violating behavior and why it might serve learning in the long run.

The elaboration of exploratory play

We apply a new quantitative method for investigating how children's exploration changes across age in order to gain insight into how exploration unfolds over the course of a human life from a life-history perspective. In this study, different facets of exploratory play were quantified using a novel touchscreen environment across a large sample and wide age range of children in the USA ( n = 105, ages = 1 year and 10 months to 12 years and 2 months). In contrast with previous theories that have suggested humans transition from more exploratory to less throughout maturation, we see children transition from less broadly exploratory as toddlers to more efficient and broad as adolescents. Our data cast doubt on the picture of human life history as involving a linear transition from more curious in early childhood to less curious with age. Instead, exploration appears to become more elaborate throughout human childhood. This article is part of the theme issue ‘Life history and learning: how childhood, caregiving and old age shape cognition and culture in humans and other animals’.

The Double-edged Sword of Pedagogy: Instruction limits spontaneous exploration and discovery

Motivated by computational analyses, we look at how teaching affects exploration and discovery. In Experiment 1, we investigated children’s exploratory play after an adult pedagogically demonstrated a function of a toy, after an interrupted pedagogical demonstration, after a naïve adult demonstrated the function, and at baseline. Preschoolers in the pedagogical condition focused almost exclusively on the target function; by contrast, children in the other conditions explored broadly. In Experiment 2, we show that children restrict their exploration both after direct instruction to themselves and after overhearing direct instruction given to another child; they do not show this constraint after observing direct instruction given to an adult or after observing a non-pedagogical intentional action. We discuss these findings as the result of rational inductive biases. In pedagogical contexts, a teacher’s failure to provide evidence for additional functions provides evidence for their absence; such contexts generalize from child to child (because children are likely to have comparable states of knowledge) but not from adult to child. Thus, pedagogy promotes efficient learning but at a cost: children are less likely to perform potentially irrelevant actions but also less likely to discover novel information.