Question

Sociologists argue that social and geographic mobility has affected our self-identities in which way?

Answer 1

Sociologists argue that social and geographic mobility has affected our self-identities because they are less stable.

Answer 2

I believe the answer is: Our self-identities are less stable.

Social and geographic mobility would force people to change the cultural and moral system that implemented in them for a long period of time, and force them to adapt to the new one. If this handled inappropriately, this could make those people have unstable self-identities.