Well, when it comes to names, at least. Nancy uncovered an Economist article from 4 years ago, which looks into the frequency of novel baby names in the US.
Dr. Alexander Bentley, along with his team at University College, London, were investigating the mathematics of cultural transmission.
For every 10,000 baby girls born, 2.3 of them are given completely novel names
For every 10,000 baby boys born, 1.6 of them are given completely novel names
It’s understandable - I think males are traditionally seen as those who continue the family name, and hence may take a more traditional first name. For girls, it’s also more acceptable to create a “pretty-sounding” name that has little or no etymological foundation.