Psychology is my second career, but my interest in it has - via a long and winding path - in part developed from my first. When I tell the readers that my previous research area was in structural geology and rock mechanics (e.g. Chadwick 1971, 1976a), while this research is, of course, on paranoia and delusional thinking, they will no doubt be astonished that there could be any connection at all between the two. To explicate the full history of how my previous research identity metamorphosed into my present one would take too long but some brief comments may be useful as they highlight the early hunches on which this investigation was partly based.