2 experiments were conducted investigating infants' use of structural relations (i.e., correlated attribute values) in dividing or segregating items into categories. Rosch argued that attribute values do not occur in all possible combinations in the real world. Even though values of attributes may vary continuously across objects, some combinations are more likely to occur than others, forming breaks or discontinuities between clusters of correlated values. Within a well-controlled laboratory context, using artificial categories and a standard infant-recognition memory procedure, the present experiments demonstrated 10-month-old infants' sensitivity to structural information like that proposed by Rosch to exist in the real world, and their ability to segregate items into categories on the basis of clusters of correlated attribute values.