I am often mistaken for younger than my actual age (31), and naturally I’m flattered. But I don’t get a swollen head about it, because I have a theory that most people “look younger than their age.”
How is this possible? Well, presumably people’s assessments of what any given age looks like are based on their previous observations of people who were that age. My idea of “what a 50-year-old looks like” is based on all the 50-year-olds I’ve met. But of course, the people I’ve met who were 50 then are all older than 50 now. This wouldn’t matter if standards of health and nutrition remained the same over time. But in fact, health and nutrition continue to improve year by year, which means that people who are 50 now probably look better than people who were 50 a decade ago looked at that time. The current 50-year-olds have had greater access to new means of preserving youth. Thus, my age assessments are biased downward systematically, unless I make a special effort to take into account improvements in preservation technology.
As evidence for my proposition, I could rely on the fact that it’s so rare to hear about someone overestimating another person’s age. But that phenomenon could result from people’s desire not to hurt each other’s feelings. So to test my hypothesis, we would need to conduct a study in which people were asked to guess ages of people in photographs or on video. The first test would check to see if the difference between age guesses and actual ages is negative and statistically significant. The second test would look to see if older people, whose observations of people stretch back further into the past, are more inclined to underestimate someone’s age than younger people.