Are you, or have you ever been, the parent of a child? If he or she got caught doing something mean to another child without any provocation, such as punching, or kicking, or maybe even biting…how effective was the excuse, “But momma–my friend Billy has been much MORE mean to other kids”? Obviously he wanted you to judge his “personal guilt” on the basis of comparison to Billy.
Did that plea work? It certainly doesn’t work with most conscientious parents! It’s extraneous information. Each child is expected to be responsible for accounting for his own behavior, not that of other children. This seems incredibly self-evident on the small scale within a family.
But for some reason I have found that many adults are comfortable trying to use the same excuse on a much wider scale, with much higher stakes. Read about this phenomenon in a new entry on my Meet MythAmerica blog.