Sociologists argue that self-identities are now more multifaceted and less stable. which is not mentioned as a factor contributing to this change?

The factor which is not mentioned is "persistent traditional social formations ".

Self-identity alludes to the worldwide understanding a man has of themselves. Self-identity is made out of moderately changeless self-evaluations, for example, identity properties, information of one's aptitudes and capacities, one's occupation and diversions, and consciousness of one's physical qualities.