> My own version of this mistake was thinking that people’s personalities were different in the past.

It's slightly surprising to me how many people think this. Like they think that boomers are selfish because that generation are more selfish people. No, people are inherently selfish.

Or old people think young people are lazier than their generation. No, pretty much everyone is and always has been lazy.

I agree; however, I also disagree: the culture and systems in which people live do affect their behavior, and the boomers moved their youth in a different world than the youth of today and that did affect them as a group and how they could express their natural pride, greed, lust, anger, gluttony, envy, and sloth