To study development researchers want to know how changes in thinking occur. when a change is gradual, linear, and quantitative, such as a child's height, development is considered to be:

continuous

Explanation:

The proponents of continuous development view that development in every aspect which includes physical, emotional, social, intellectual, etc is a gradual continuous process. Development psychologist believed that development is a continuous life long process. They view that development at one stage provides the base for the development at next stage. For example, first, a child learns to crawl then sit and then finally walks.

its d i know cause i've been googling it