According to the intuitive rules theory, students are affected by a small number of intuitive rules when solving a wide variety of science and mathematics tasks. The current study considers the relationship between students' Piagetian cognitive levels and their tendency to answer in line with intuitive rules when solving comparison tasks. The findings indicate that the tendency to answer according to the intuitive rules varies with cognitive level. Surprisingly, a higher rate of incorrect responses according to the rule "same A-same B" was found for the higher cognitive level. Further findings and implications for science and mathematics education are discussed.