Descriptions of the schizoid personality as "hidden" behind an outward appearance of emotional engagement have been recognized since 1940, with Fairbairn's description of "schizoid exhibitionism", in which the schizoid individual is able to express a great deal of feeling and to make what appear to be impressive social contacts yet in reality gives nothing and loses nothing. Because they are "playing a part", their personality is not involved. According to Fairbairn, "the person" disowns the part he is playing, and the schizoid individual seeks to preserve his personality intact and immune from compromise. The schizoid's false persona is based around what those around them define as normal or good behaviour, as a form of compliance. Further references to the secret schizoid come from Masud Khan, Jeffrey Seinfeld and Philip Manfield, who give a description of an SPD individual who "enjoys" public speaking engagements but experiences great difficulty in the breaks when audience members would attempt to engage him emotionally. These references expose the problems in relying on outer observable behavior for assessing the presence of personality disorders in certain individuals.