Which factor was NOT identified as a source of vulnerability in research according to the NBAC?

The factor identified as NOT being a source of vulnerability in research according to the National Bioethics Advisory Commission (NBAC) is the high potential for individual benefit. In research ethics, vulnerability typically refers to conditions that may increase the risk of harm or exploitation of participants. These can include high risk of harm from participation, situational cognitive vulnerabilities that may impair a person's ability to make informed decisions, and the presence of coercion that may compromise a participant’s ability to voluntarily agree to participate.

On the other hand, the potential for individual benefit is generally considered a positive aspect of research participation, rather than a source of vulnerability. When participants perceive that they could gain significant personal benefits—such as access to new treatments or therapies—they may be more inclined to participate. However, this potential benefit does not inherently make them vulnerable; instead, it can serve as a motivation for participation. Therefore, this factor stands out as one that does not align with the typical sources of vulnerability outlined by the NBAC.