Is this name male or female?

The one-way street

Names drift between the sexes, and they almost always drift the same direction: from boys to girls. Ashley, Leslie, Shannon, Kelly, Madison and Avery were all predominantly male at some point in American record-keeping, and all are now overwhelmingly female. The reverse is rare enough that researchers treat it as the exception. Once a name reaches roughly a quarter female, the shift tends to accelerate and finish.

What counts as unisex

Very few names sit near a true even split and stay there. We call a name genuinely unisex when it falls between 40% and 60% male across all recorded births, which is a small club — names like Jordan, Riley and Finley have all passed through that band, usually on their way somewhere else. The decade view is the interesting part: a name sitting at 50% overall may be the average of a male past and a female present rather than a steady balance.

Where the data comes from

Social Security birth registrations record a sex alongside each name, which is what makes this measurable at all. The figures describe how names were registered at birth, so they reflect naming convention rather than anything about the people who carry them.