Last month, FlowingData crunched some numbers to come up with the 35 most unisex baby names in the U.S. since 1930. Here’s the list:
I’m not sure exactly what criteria were used to create the rankings, but it looks like the top unisex names on this list were the top-1,000 names that “stuck around that 50-50 split” the longest from 1930 to 2012.
(In contrast, my unisex baby names page lists any name on the full list to fall within the 25-75 to 75-25 range, but only in the most recent year on record.)
The FlowingData post also mentions that, though the data is pretty noisy, there might be “a mild upward trend” over the years in the number of babies with a unisex name.
**In 1957, Johnny Carson’s 5-year-old son Kim had his name changed to Richard because he’d been having “a little trouble over his name being mistaken for a girl’s.”
[Update, 11/7/2013: Changed Michael to Michel.]