Four-year-old Mia watched her mother sing while she was brushing her hair. The next day, Mia's mother saw Mia singing while brushing her dog. Mia acquired the behavior through learning.

Modeling.

Explanation:

In Psychology, there is a theory called modeling and the theory talks about how one may change his or her ways of thinking because he or she notice or observe other person's Behavior. Also in a branchn of Psychology, modeling is just about a method or technique in psychotherapy but in this question we are talking about the first or former meaning rather than the latter one.

In the question we have that the daughter named Mia copied what her mother use to do while doing work, especially while washing hairs so the daughter started doing likewise it means that Mia, that is the daughter got her Behavior from her just buy observing her ways of doing things and the term is called modeling.