A kind of metonymic ICM. Members of some categories are 'generated' by a core subset of category members called generators. These generators are judged to be more prototypical than the other category members that they generate and thus stand for the entire category. For example, the natural numbers are represented by the set of integers between zero and nine, which are combined in various ways in order to produce higher natural numbers. For instance, the number 10 combines the integers 1 and 0. Thus, the entire category natural numbers is generated from a small subset of single-digit integers.

This is why the numbers 1 to 9 are judged as more prototypical members of the category natural numbers than much larger numbers.