You might wonder how people who seem so good by occupation could be so bad in private. The theory of moral licensing could help explain why: When humans are good, it says, we give ourselves license to be bad.

In one paper, economists at the University of Chicago reported that working for a socially responsible company motivated employees to act immorally. In one experiment, people were hired to transcribe images of short German texts and paid 10 percent upfront, with the remaining payment being delivered if they completed the transcriptions, or if they declared the documents too illegible to transcribe. When they were told that, for every job completed or marked illegible, 5 percent of their wages would be donated to Unicef’s educational programs, the instances of cheating rose by 25 percent, compared to where no charitable donation was offered. Cheating manifested in both workers not completing jobs (taking the 10 percent upfront fee and running) and also workers saying that documents were too illegible to transcribe (and so receiving the full fee).