Verbal and nonverbal forms of thinking exhibit widespread dissociation at neural and behavioral level. The importance of this for children's causal thinking and its implications for school science are largely unknown. Assessing 5- to 10-year-olds' responses (N = 231), verbal ability predicted causal reasoning, but only at lower levels, while nonverbal ability was the strongest predictor at higher levels of causal inference. We also distinguished between generic and scientific vocabulary use (n = 101). The results showed that use of scientific vocabulary predicted causal reasoning beyond generic, and connected more to nonverbal thinking. The findings highlighted the importance of elementary school science activities supporting application of nonverbal ability in thinking about causal processes; the benefits of linking nonverbal imagery to scientific vocabulary; and shortcomings in understanding of the forms/sources of nonverbal ability and their role in learning.