Four-year-old Alex and his mother visited the zoo. While they were there, Alex’s mother took him to see the squirrel exhibit. Alex saw many different types of squirrels, but when he saw a flying squirrel glide from one branch to the next he pointed and said, "A bird." Considering Piaget’s work, Alex is demonstrating an example of:

The answer is assimilation.

Explanation:

According to Piaget, assimilation is a process in which we aquire new information and incorporate it to our existing knowledge. This often occurs by interpreting new experiences according to our previous ideas. In the example, Alex assimilates a flying squirrel as a bird because of his preexisting knowledge of birds (e.g. they fly).

It's possible to change one's knowledge through a process called accodomation, something Alex will likely do in the future: he will learn that birds have feathers and beaks, and that some squirrels can glide in the air.  

answer; basic psychology;