This article focuses on the ability of elementary school children to provide scientific reasoning on several paper-and-pencil tasks. Fourth graders participated in this study and the purpose was to find whether the four different dimensions comprising scientific reasoning in children are influenced by both general cognitive abilities, like reading ability and intelligence, as well as by more specific cognitive skills, such as inhibition, spatial abilities and problem-solving abilities. It was concluded that all these cognitive factors, except for inhibition (for which no safe conclusion could be drawn), are in direct correlation with scientific reasoning, with problem-solving skills bearing the highest correlation. Thus, it is from a very early age that complex cognitive skills are developed in humans, and they all seem to be interconnected fostering the development of reasoning abilities.