He quotes an Israeli study which showed that when graphologists were shown strictly neutral texts with no relevant information about the candidate - their level of performance plummeted.

BBC: A French love affair... with graphology

According to Begue, most graphologists are able to pull off the trick because they use the content of candidates' letters - the detail about their lives, motivation and so on - to draw up a psychological profile.

BBC: A French love affair... with graphology