Adam Mastroianni was always bothered by anecdotal claims that people are becoming less kind, respectful and trustworthy over time. So he took a deep dive into such claims: he wrote a PhD dissertation.

Now Mastroianni and a collaborator have drawn on decades’ worth of survey results and other data to find that people around the world have perceived a general moral decline for at least the past 70 years1. But the data also show that individuals’ evaluation of their contemporaries’ morality has remained largely unchanged during that time. Mastroianni, a psychologist at Columbia University in New York City, and his co-author Daniel Gilbert, a psychologist at Harvard University in Cambridge, Massachusetts, conclude that the perception of moral decline is an illusion.

The findings were published in Nature on 7 June.