In the 1970s, as adoption search and support organizations developed, there were challenges to the language in common use at the time. As books like Adoption Triangle by Sorosky, Pannor and Baran were published, and support groups formed like CUB (Concerned United Birthparents), a major shift from "natural parent" to "birthparent" occurred. Along with the change in times and social attitudes came additional examination of the language used in adoption.
Externally focused theories, in contrast, suggest that reunion is a way for adoptees to overcome social stigma. First proposed by Goffman, the theory has four parts: 1) adoptees perceive the absence of biological ties as distinguishing their adoptive family from others, 2) this understanding is strengthened by experiences where non-adoptees suggest adoptive ties are weaker than blood ties, 3) together, these factors engender, in some adoptees, a sense of social exclusion, and 4) these adoptees react by searching for a blood tie that reinforces their membership in the community. The externally focused rationale for reunion suggests adoptees may be well adjusted and happy within their adoptive families, but will search as an attempt to resolve experiences of social stigma.