America Ran Out of Common Names

Every year since 1910, the Social Security Administration has counted every first name given to five or more babies in each state. It is close to a perfect cultural record: near-universal, annual, and unpolluted by what people say they value. What it shows, over 116 years, is a country steadily abandoning the idea that a name should be ordinary.

In 1950, the ten most popular boys' names covered 35.2% of all boys born; the girls' top ten covered 25.6%. By 2025 both figures had fallen to around 9%. Measured as an effective number of names — the diversity index economists use for market concentration, applied to nurseries — boys went from the equivalent of 58 equally-common names to 347; girls from 89 to 429, still climbing.

The turn is precisely datable: boys' top-10 share peaks in the late 1940s and erodes slowly until 1990, then falls off a cliff. Girls led the whole way — female naming has been more diverse than male naming in every single year since 1910.

1  Look up any name

Aggregate indices hide the fun. The 2,163 names below are every name that ever reached 0.05% of same-sex births. Some are mountains (Linda's 1948 peak — 6.03% of all girls, the largest single-name year in the record, powered in part by a hit song). Some are mesas (Elizabeth, essentially flat for a century). Some are needles: Ayden, Nevaeh, Brittany — up and down within a generation.

2  Fads burn faster now

Define a name's rise time as the years it takes to climb from a quarter of its eventual peak to the peak, and its fall time as the years to sink back below a quarter of peak. For names that peaked in the 1920s–40s, the median fall took 24–27 years — a name was a generation-scale commitment. For names peaking in the 1990s–2000s the median fall is 14–16 years and still shrinking. The rise has always been quick; what changed is how fast America moves on.

3  The one-way frontier

Names cross the gender line — almost always in one direction. Leslie, Ashley, Aubrey, Sydney: each began as a boys' name and became, within a few decades, overwhelmingly a girls' name. The reverse journey is nearly absent from the record. The pattern is so regular it has a sociological name — parents colonize "distinguished" male names for daughters, after which they become unavailable for sons.

4  Watching a name conquer the country

Names diffuse through the states like any innovation. Jennifer ignites in the late 1960s — earliest and hottest on the coasts — saturates the whole country by 1972, and recedes everywhere in near-unison. Nevaeh ("heaven" backwards) starts in 2001 from nothing, after a musician named his daughter Nevaeh on MTV, and spreads inland with the geography reversed — strongest in the heartland, weakest on the coasts. Drag the slider.

What unites these panels is a single long trend: naming has moved from a convention you follow to a statement you compose. The cost of that freedom is churn — the faster fads of Figure 3 — and its perimeter keeps expanding: the SSA now records about twice as many distinct names per year as it did in 1950, even as births have fallen.