One of the points made in the explanation of societal devaluation, in the SRV monograph authored by Wolfensberger (e.g., page 40 in the 4th expanded edition) and in SRV leadership level workshops, is that societal devaluation (negative perception followed by negative treatment) of a group can become multi-generational. This 2013 book entitled ‘No Place to Call Home: Inside the Real Lives of Gypsies and Travellers’ presumably is a history of such devaluation.
Especially relevant to Social Role Valorization, the reviewer lists several examples of wounds (lack of education and access to health care, lowered life expectancy, negative imagery, abuse and violence).
This might be a book worth reviewing for The SRV Journal, and/or studying as part of an SRV discussion group.