Among the Lehigh Valley residents whose trick-or-treat night is Thursday, October 31, there are likely to be many families and individuals who will not be available to hand out candy during the scheduled time of 6 p.m. to 8 p.m. Although one option is certainly to leave porch lights off to indicate a treat-less house, many residents prefer to leave a large basket of candy from which trick-or-treaters can self-serve. The main problem with this approach is that a few unscrupulous trick-or-treaters may empty the basket by taking several treats, thus depriving other neighborhood children.
Local families have developed several methods of deterrence, including positioning the basket of candy near a Halloween decoration that appears to be a real person, such as a realistically stuffed scarecrow or vampire. However, the best option may be the simplest: forcing the would-be thieves to confront their own image as they double-dip. According to research published in October 1979 in the Journal of Personality and Social Psychology, "self-awareness induced by the presence of a mirror placed behind the candy bowl decreased transgression rates for children who had been individuated by asking them their name and address."
A few problems plague this approach. First, the researchers noted that the presence of the mirror "did not affect the behavior of the children left anonymous." Second, "[s]elf-awareness influenced older, but not younger children." However, it may be possible to correct for the first issue with cleverly worded signage ("I know who you are"), and the second issue may be less problematic in 2013 than it was in 1979, as parents are now generally inclined to trick-or-treat with their young children. Then again, maybe the "please take only one" sign is the best idea.