What causes STIGMA?

In Greek society, stizein was a mark placed on slaves to identify their position in the social structure and to indicate that they were of less value. The modern derivative, stigma, is therefore understood to mean a social construction whereby a distinguishing mark of social disgrace is attached to others in order to identify and to devalue them. Thus, stigma and the process of stigmatiza- tion consist of two fundamental elements, the recognition of the differentiating ‘mark’ and the subsequent devaluation of the person.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1489829/pdf/wpa010025-b.pdf

2 parts to STIGMA

1st - You mark them; like with diagnosis.

2nd - You devalue them. This is what we all fear.

What do you think causes STIGMA?