Is there any data behind the stated trend towards narcissism in recent generations or is it just a guess from some cranky old people? Any study performed on tod

Is there any data behind the stated trend towards narcissism in recent generations or is it just a guess from some cranky old people? Any study performed on today's university students tells me nothing about the university students of 20 or 30 years ago - is it possible that university students have always been deprived of self-esteem? Is it further possible that humans naturally exhibit insecurity?