Three-year-old Zara calls all four-legged animals ""kitties."" Her tendency to fit all four-legged animals into her existing conception of a kitten illustrates the process of?

Assimilation

Explanation:

Jean Piaget was a psychologist who developed a theory of cognitive development, according to which people go through different stages in their cognitive development starting since birth and until adolescence. In each stage the mental processes become more and more logic and abstract.

One of the processes that Piaget defined was the process of assimilation. Through assimilation we can take in new information from the world and incorporate in our already existing ideas or schemes. In other words, we fit new information into things that we already know.

In this example, Zara has the tendency of fitting all four-legged animals into her existing conception of a kitten. We can see that Zara already has an idea of what a kitten is and she is taking in the new information (the new four-legged animals she sees) and fitting them into the scheme of kitten she already know. Therefore, this illustrates the process of assimilation.