Well this is not my field, but as far as I can see the study (DOI helpfully at the bottom of the OP) was published in a journal called "Self and Identity" and according to http://www.issiweb.org/ this is peer reviewed.

The official journal of ISSI is Self and Identity, which is published by Psychology Press. Self and Identity is a peer-reviewed academic journal that focuses on research and theory relevant to the aims of the society.

Could you clarify your remark further?