Cognitive and home predictors of precocious reading and math before formal education

•Cognitive and home predictors of reading and math were assessed systematically.•We focused on precocious learners, before the onset of formal education.•Reading and math were studied concurrently, to assess their co-development.•Precocious reading was predicted by literacy-related skills and formal activities.•Results suggest qualitative differences for precocious vs. typical math learners. Children start formal schooling with substantial individual differences in their early literacy and numeracy abilities, but little is known about predictors of precocious (i.e., early advanced) reading and math. In this study, we investigated contributions from a range of cognitive and home-related predictors to early reading, arithmetic and applied math in 224 Dutch kindergartners (Mage = 5 years 5 months). Our results showed that precocious reading and math were differentially predicted by specific combinations of domain-specific, domain-general, and cross-domain cognitive skills. For reading, we primarily observed contributions from literacy-specific skills, especially letter knowledge. For mathematics, we observed contributions from various domain-specific, domain-general, and cross-domain cognitive skills. Predictors of “basic” arithmetic skills differed from predictors of “precocious” arithmetic fluency, suggesting qualitative differences between typical and precocious learners. Contributions from children’s home environments (parental education levels and parent–child activities) remained relatively small across all models. Together, our results provide novel insights into the (co–)development of precocious reading and math in preschool-aged children.