We traced the development of sensitivity to symmetric relational patterns by creating a symmetry match-to-sample task. Children saw a symmetric standard made up of two shapes and choose between two novel alternatives: a symmetric pair and an asymmetric pair. We found that young children chose randomly between the two alternatives. Children were not reliably above chance until 8-to 9 years of age. In a second study, we found that young children could succeed in making symmetric relational matches if the triads were designed to invite informative comparisons. These findings show that relational insight of symmetry develops relatively late. However, as with other relations, comparison processes can promote sensitivity to the symmetry relation.

Relational processing is critical for complex cognition (Gentner, 2003, 2010). Here, we investigate the development of twofundamental relationssame and different. Previous research suggests that childrens understanding of same may precede un-derstanding of different, and that languageespecially labels for these relationsmay support this understanding (Hochmannet al., 2017; Christie & Gentner, 2014). We presented 4-year-olds with either a different-only or a same/different mixedversion of the Relational-Match-to-Sample (RMTS) task. Children made relational matches at above-chance rates inboth conditions and performance was comparable with previous findings on a same-only RMTS (Christie & Gentner,2014; Hoyos, Shao, & Gentner, 2016; replication in process). Across both conditions, children who said the wordssame/different outperformed those who did not, suggesting that spontaneous production of the terms indicated better en-coding of the relations. Interestingly, children produced the word same more than the word different, even when presentedwith match-to-different trials.

Recent studies report a striking decline in children’s ability to notice same-different relations around age 3 (Walker et al., 2015). We propose that such a decline results from an object focus related to children’s avid noun-learning. To test this, we examine children’s performance on a classic relational task – the relational match-to-sample task (RMTS). Prior work has shown that 4-year-olds can pass this task (Christie & Gentner, 2014). However, if nominal language induces an object focus, their performance should be disrupted by a noun-labeling pretask. In two experiments, 4-year-olds either labeled objects or actions in a naming pretask. Then they completed the RMTS task. Consistent with the noun-focus explanation, the object-naming group failed the RMTS task, whereas the action-naming group and a control group both succeeded. This suggests that nominal language can lead to an object focus, and that this could explain the temporary decline in children’s relational processing.

Relational ability—the ability to compare situations or ideas and discover common relations – is a key process in higher-order cognition that underlies transfer in learning and creative problem solving. For this reason, it has generated intense interest both among developmentalist and in cross-species comparative studies. The gold standard for evaluating relational ability is the Relational-Match-to-Sample (RMTS) task (Premack, 1983). Current work in cognitive development has produced inconsistent results as to when children are able to pass the RMTS, with Christie and Gentner (2014) finding earlier success than Hochmann et al. (2017) and Kroupin and Carey (2022). In this research, we attempt to resolve this issue. We first describe two studies that bear out and extend Christie and Gentner’s (2014) findings. We then discuss factors that might explain the discrepancy between the findings.