The development of scientific reasoning: Hypothesis testing and argumentation from evidence in young children

The complex associations between scientific reasoning and advanced theory of mind

This 6-wave longitudinal study (2014-2018) of 161 German 5- to 10-year-olds from a midsized city and rural area in southern Germany (89 females, 72 males; predominantly White; mostly middle class) found that scientific-reasoning abilities first develop at 6 years. Abilities were highly stable, with the kindergarten score predicting 25% of end-of-elementary-school variance. Individual but not developmental differences were related to language abilities (0.39), mindreading skills (0.33), and parental education (0.36). In early elementary school, mindreading skills predicted scientific reasoning (0.15), but not vice versa; in late elementary school, bidirectional associations emerged (0.11-0.33). Our findings suggest that mindreading is a precursor for the development of scientific reasoning and that older children use scientific reasoning to revise their advanced theories of mind.

Contributions of causal reasoning to early scientific literacy

Although early causal reasoning has been studied extensively, inconsistency in the tasks used to assess it has clouded our understanding of its structure, development, and relevance to broader developmental outcomes. The current research attempted to bring clarity to these questions by exploring patterns of performance across several commonly used measures of causal reasoning, and their relation to scientific literacy, in a sample of 3- to 5-year-old children from diverse backgrounds (N = 153). A longitudinal confirmatory factor analysis revealed that some measures of causal reasoning (counterfactual reasoning, causal learning, and causal inference), but not all of them (tracking cause-effect associations and resolving confounded evidence), assess a unidimensional factor and that this resulting factor was relatively stable across time. A cross-lagged panel model analysis revealed associations between causal reasoning and scientific literacy across each age tested. Causal reasoning and scientific literacy related to each other concurrently, and each predicted the other in subsequent years. These relations could not be accounted for by children's broader cognitive skills. Implications for early STEM (science, technology, engineering, and math) engagement and success are discussed.

Developmental Trajectories in Diagnostic Reasoning: Understanding Data Are Confounded Develops Independently of Choosing Informative Interventions to Resolve Confounded Data

Two facets of diagnostic reasoning related to scientific thinking are recognizing the difference between confounded and unconfounded evidence and selecting appropriate interventions that could provide learners the evidence necessary to make an appropriate causal conclusion (i.e., the control-of-variables strategy). The present study investigates both these abilities in 3- to 6-year-old children (N = 57). We found both competence and developmental progress in the capacity to recognize that evidence is confounded. Similarly, children performed above chance in some tasks testing for the selection of a controlled test of a hypothesis. However, these capacities were unrelated, suggesting that preschoolers' nascent understanding of the control-of-variables strategy may not be driven by a metacognitive understanding that confounded evidence does not support a unique causal conclusion, and requires further investigation.

A Model of Scientific Data Reasoning

Data reasoning is an essential component of scientific reasoning, as a component of evidence evaluation. In this paper, we outline a model of scientific data reasoning that describes how data sensemaking underlies data reasoning. Data sensemaking, a relatively automatic process rooted in perceptual mechanisms that summarize large quantities of information in the environment, begins early in development, and is refined with experience, knowledge, and improved strategy use. Summarizing data highlights set properties such as central tendency and variability, and these properties are used to draw inferences from data. However, both data sensemaking and data reasoning are subject to cognitive biases or heuristics that can lead to flawed conclusions. The tools of scientific reasoning, including external representations, scientific hypothesis testing, and drawing probabilistic conclusions, can help reduce the likelihood of such flaws and help improve data reasoning. Although data sensemaking and data reasoning are not supplanted by scientific data reasoning, scientific reasoning skills can be leveraged to improve learning about science and reasoning with data.

Rethinking the "gap": Self-directed learning in cognitive development and scientific reasoning

To improve upon their current knowledge, learners must be able to generate informative data and accurately evaluate this evidence. However, there is substantial disagreement regarding self-directed learners' competence in these behaviors. Researchers in cognitive development have suggested that learners are "intuitive scientists," generating informative actions and rationally coordinating their current observations and prior beliefs from an early age. Conversely, researchers in scientific reasoning report that learners struggle with experimentation and often fail to reach appropriate conclusions from evidence, even as adults. According to the prevailing narrative, these inconsistent findings must be "bridged" to explain the gap between learners' successes and failures. Here, we advocate for an alternative approach. First, we review the research on scientific reasoning and find that there may be less evidence for learners' failures than is typically assumed. Second, we offer a novel interpretation that aims to account for both literatures: we suggest that self-directed learners may be best understood as competent causal reasoners. That is, many seemingly uninformative or irrational behaviors are consistent with the goals of causal learning. This account not only resolves the apparent contradictions in the existing research, but also offers a way forward towards a more accurate and integrated understanding of self-directed learning. This article is categorized under: Psychology > Development and Aging Psychology > Learning Psychology > Reasoning and Decision Making.

Individual Differences in Children’s Scientific Reasoning

Scientific reasoning is an important skill that encompasses hypothesizing, experimenting, inferencing, evaluating data and drawing conclusions. Previous research found consistent inter- and intra-individual differences in children’s ability to perform these component skills, which are still largely unaccounted for. This study examined these differences and the role of three predictors: reading comprehension, numerical ability and problem-solving skills. A sample of 160 upper-primary schoolchildren completed a practical scientific reasoning task that gauged their command of the five component skills and did not require them to read. In addition, children took standardized tests of reading comprehension and numerical ability and completed the Tower of Hanoi task to measure their problem-solving skills. As expected, children differed substantially from one another. Generally, scores were highest for experimenting, lowest for evaluating data and drawing conclusions and intermediate for hypothesizing and inferencing. Reading comprehension was the only predictor that explained individual variation in scientific reasoning as a whole and in all component skills except hypothesizing. These results suggest that researchers and science teachers should take differences between children and across component skills into account. Moreover, even though reading comprehension is considered a robust predictor of scientific reasoning, it does not account for the variation in all component skills.

Preschool Children Rarely Seek Empirical Data That Could Help Them Complete a Task When Observation and Testimony Conflict

Children (N = 278, 34-71 months, 54% girls) were told which of two figurines turned on a music box and also observed empirical evidence either confirming or conflicting with that testimony. Children were then asked to sort novel figurines according to whether they could make the music box work or not. To see whether children would explore which figurine turned on the music box, especially when the observed and testimonial evidence conflicted, children were given access to the music box during their sorting. However, children rarely explored. Indeed, they struggled to disregard the misleading testimony both when sorting the figurines and when asked about a future attempt. In contrast, children who explored the effectiveness of the figurines dismissed the misleading testimony.

Young children's metacognitive awareness of confounded evidence

Young children selectively explore confounded evidence-when causality is ambiguous due to multiple candidate causes. This suggests that they have an implicit understanding that confounded evidence is uninformative. This study examined explicit understanding, or metacognitive awareness, of the informativeness of different qualities of evidence during early childhood. In two within-participants conditions, children (N = 60 5- and 6-year-olds) were presented with confounded and unconfounded evidence and were asked to evaluate and explain their knowledge of a causal relation. Children more frequently requested further information in the confounded condition than in the unconfounded condition. Nearly half of them referred to multiple candidate causes when explaining confounded evidence. Our data demonstrate that young children can reason explicitly about the informativeness of different kinds of evidence.

Preschoolers' Induction of the Concept of Material Kind to Make Predictions: The Effects of Comparison and Linguistic Labels

Analogical reasoning by comparison is considered a special case of inductive reasoning, which is fundamental to the scientific method. By reasoning analogically, learners can abstract the underlying commonalities of several entities, thereby ignoring single objects' superficial features. We tested whether different task environments designed to trigger analogical reasoning by comparison would support preschoolers' induction of the concept of material kind to predict and explain objects' floating or sinking as a central aspect of scientific reasoning. Specifically, in two experiments, we investigated whether the number of presented objects (one versus two standards), consisting of a specific material and the labeling of objects with the respective material name, would benefit preschoolers' material-based inferences. For each item set used in both experiments, we asked the children (N = 59 in Experiment 1, N = 99 in Experiment 2) to predict an object's floating or sinking by matching it to the standards and to verbally explain their selections. As expected, we found a significant effect for the number of standards in both experiments on the prediction task, suggesting that children successfully induced the relevance of material kind by comparison. However, labels did not increase the effect of the standards. In Experiment 2, we found that the children could transfer their conceptual knowledge on material kind but that transfer performance did not differ among the task environments. Our findings suggest that tasks inviting analogical reasoning by comparison with two standards are useful for promoting young children's scientific reasoning.

Developing an Understanding of Science

Young children are adept at several types of scientific reasoning, yet older children and adults have difficulty mastering formal scientific ideas and practices. Why do “little scientists” often become scientifically illiterate adults? We address this question by examining the role of intuition in learning science, both as a body of knowledge and as a method of inquiry. Intuition supports children's understanding of everyday phenomena but conflicts with their ability to learn physical and biological concepts that defy firsthand observation, such as molecules, forces, genes, and germs. Likewise, intuition supports children's causal learning but provides little guidance on how to navigate higher-order constraints on scientific induction, such as the control of variables or the coordination of theory and data. We characterize the foundations of children's intuitive understanding of the natural world, as well as the conceptual scaffolds needed to bridge these intuitions with formal science.

Individual Differences in Children's Development of Scientific Reasoning Through Inquiry-Based Instruction: Who Needs Additional Guidance?

Scientific reasoning involves a person's ability to think and act in ways that help advance their understanding of the natural world. Young children are naturally inclined to engage in scientific reasoning and display an emerging competence in the component skills of, for example, hypothesizing, experimenting and evaluating evidence. Developmental psychology research has shown that same-age children often differ considerably in their proficiency to perform these skills. Part of this variation comes from individual differences in cognition; another part is due to the fact that the component skills of scientific reasoning emerge at a different age and mature at a different pace. Significantly less attention has been paid to children's capacity to improve in scientific reasoning through instruction and deliberate practice. Although elementary science lessons are generally effective to raise the skill level of a group of learners, not all children benefit equally from the instructional treatment they receive. Knowing what causes this differential effectiveness is important as it can inform the design of adaptive instruction and support. The present study therefore aimed to identify and explain how fifth-graders (N = 138) improve their scientific reasoning skills over the course of a 5-week inquiry-based physics unit. In line with our expectations, significant progress was observed in children's achievements on a written scientific reasoning test, which was administered prior to and after the lessons, as well as in their responses to the questions and assignments that appeared on the worksheets they filled out during each lesson. Children's reading comprehension and mathematical skillfulness explained a portion of the variance in children's pretest-posttest gain. As these overall results did not apply equally to all component skills of scientific reasoning, we recommend science teachers to adapt their lessons based on children's past performance in reading and math and their actual performance of each scientific reasoning skill. The orchestration and relative effectiveness of both adaptive science teaching approaches is an interesting topic for future research.