Testing children's ability to correctly use the "Shadow Rule" for sun protection.

Introduction: The "Shadow Rule" (SR) is a useful, immediate indicator of sunburn risk following the mnemonic "Short shadow? Seek shade!" However, some question people's ability to discern when their shadows are shorter or longer than them.

Methods: N = 76 10-year-old children were taught the SR and then asked to estimate their sun-cast shadow length relative to their height and whether this meant they should seek shade. Children were then asked to estimate a doll's shadow length at 10 systematically randomised angles.

Results: Children experienced greatest difficulty judging their shadows' lengths when they were equal to their height. At all other angles, they demonstrated high accuracy and 92 % of the time on average could correctly interpret the SR.

Conclusions: Ten-year-old children appear capable, and by extension adults too, of applying the SR. Future research is now required to establish if education about the SR will translate into sun protection behaviour change.