There are a few names I think are being confused. Jan, short for Janice is a female name, but Jan in Central / Eastern Europe as a form of John is masculine. Jean the female name and Jean the french male name are different.

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cvhc 2 hours ago | parent | next [-]

Yeah immigration and mix of similar names from different languages could also be reasons for the (at least perceived) shifts.

	▲	nostrademons an hour ago \| parent [-]
		This is part of what they mean by girl names driving the shift. You have a traditional ethnic name that may be masculine or feminine and has a baseline low level of popularity. Then you have a popular female name that rapidly gains and loses its popularity. The effect on the mix is that it's shifting from masculine to feminine, but really you should look at it as a newly-popular female name being layered on top of the traditional name. And you can often see this in the timescale, with a clear pop-culture trigger leading to the rising girl name. Looking at just part of the data, I can see this with Arya (Stark, Game of Thrones), Paris (Hilton), Stevie (Nicks, of Fleetwood Mac), Dakota (Fanning), and Tatum (O'neal), and the masculine trend also relates to the fading of generationally-popular names like Jean (Silent/Boomer), Pat (Boomer), Joan (Silent/Boomer), Courtney (Gen-X/Xennial), etc.

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dotancohen 22 minutes ago | parent | prev | next [-]

Kim is another good one - I've met several Korean men named Kim.

Though I'm not 100% sure they weren't using their family name as their everyday identity name (the Kims I met were not related).

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mikepurvis an hour ago | parent | prev | next [-]

I was going to say the same about Jean; I think that one at least is hard to really draw conclusions from without additional data like languages spoken at home.

Anecdotally, the boy->girl names are almost all very popular names where I've met multiple each of those across different ages, whereas the other two categories feel like they have a lot more down-list entries.

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crooked-v an hour ago | parent | prev [-]

Going by the peak time on the chart, Jean flipped over fast right about when Jean-Luc entered public consciousness.