Does "in group" refer back to "the stigmatized group"?

[NewHopeR]

Although several psychological theories predict that members of stigmatized groups should have low global self-esteem, empirical research typically does not support this prediction. It is proposed here
that this discrepancy may be explained by considering the ways in which membership in a stigmatized group may protect the self-concept. It is proposed that members of stigmatized groups may (a) attribute negative feedback to prejudice against their group, (b) compare their outcomes with those of the ingroup, rather than with the
relatively advantaged outgroup, and (c) selectively devalue those dimensions on which their group fares poorly and value those dimensions on which their group excels. Evidence for each of these processes and their consequences for self-esteem and motivation is reviewed. Factors that moderate the use of these strategies and implications of this analysis for treatment of stigmas are also discussed. (PsycINFO Database Record (c) 2012 APA, all rights
reserved)

[5jj]

No. The stigmatised group are shut out of the in-group.

[NewHopeR]

No. The stigmatised group are shut out of the in-group.

So the former is originally a part of the ingroup?

[5jj]

So the former is originally a part of the ingroup?

There is no evidence of that in the passage.

[Barb_D]

I don't think that's what was meant. I think they mean that within themselves, they are "ingroup" -- not the same as the "in" (where "in" = popular) group. That is, they compare themselves only to others in their same group, not against the others who have more advantages and who are not in their group.

[Tdol]

I agree- ingroup means the group people feel they belong to rather than the in-group (crowd).
Ingroups and outgroups - Wikipedia, the free encyclopedia

(Mind you, I will admit to being part of the outgroup on these definitions until I searched)