Glossary
Psychological Acceptability
Psychological acceptability holds that a security mechanism has to be usable enough that the people subject to it actually go along with it, because a mechanism people find too burdensome doesn't stay effective — it gets bypassed, worked around, or quietly disabled by the very people it was meant to protect. A control that's theoretically sound but practically unbearable provides essentially none of its intended protection once people find a way around it.
This isn't an argument for weakening security to make it convenient; it's a recognition that a mechanism's actual, real-world effectiveness depends on adoption, and a mechanism nobody actually follows protects nothing regardless of how well it was designed on paper. Designing for real-world adoption is part of the security design problem, not a separate concern layered on afterward.