King's College London

"Lack of moral fibre" (LMF), a term introduced by the Royal Air Force in April 1940, was designed to stigmatize aircrew who refused to fly without a medical reason. This article explores the justification for this uncompromising policy, research by neuropsychiatrists into the psychological effects of aerial combat, and their attempts to modify LMF procedures. The reasons why the British Army and Royal Navy did not formally adopt the policy are analyzed in relation to the military context. What happened to airmen subjected to LMF assessment and treatment programs is also discussed in relation to recent British initiatives.