Right, you just need to vulgarize it into six year old.

And into thirty nine year old while you're at it.

OK :

6 year old : You got nails ----> you are adapted to a selective pressure that counter-selects individuals that can't wear nail varnish. Therefore your chances of transmitting your genetic patrimony are increased.

39 year old : You got nails ----> you get nailed more often.

Ca va comme ça ?