"Patterning" is a cognitive intervention that is unknown to psychologists, but has nevertheless been taught for half a century in nearly all kindergartens and many preschools in English-speaking countries. Patterning is the understanding that a certain rule governs the sequence of items in a series. At the simplest level, if the series has been red, tan, red, tan, red, tan, the next item should be red. More advanced patterns--"growing" geometric patterns and complex patterns of letters, numbers, and objects--have also been studied. Patterning is thought by educators to be a key cognitive ability that promotes academic achievement. However, its relative position in the hierarchy of cognitive developments is unknown. The present study showed that it is closely related to both transitivity and seriation, and that size transitivity problems best expressed the common factor that predicted patterning scores. [This article was published in "Psychology" v9 p2073-2082 2018.]