Eye-witnesses should not do cryptic crosswords prior to identity parades.

Navon letter tasks have been shown to affect subsequent face recognition performance. As such tasks are not likely to by carried out prior to a witness attending an identity parade this is unlikely to have much applied relevance. Here, however, it is explored how a range of puzzles that witnesses might engage in affect face recognition. Cryptic crosswords were found to have a detrimental effect on subsequent face recognition, unlike reading, literal crosswords, or sudoku. As well as this finding's practical importance, it also provides a further insight into the Navon effect on face processing.