There are trendy baby names, and then there are baby name trends.

That may not seem like much of a distinction, but with each passing year the difference is growing. Trends are moving away from individual names and toward sounds and styles. A look at two name trends from two different eras tells the tale.

Old-School Trends

Back when Michael and David were America’s favorite names, nobody was inspired to create “Pichael” or “Zavid.” Traditional names were received objects, authorized and elevated by cultural forces outside of the family. If a new sound or style came into fashion, parents mostly chose from the established pool of names that fit.

For example, one of the biggest sound trends of past generations was the -ald ending for boys, as in Ronald, Donald, and Gerald. The style first started to take off toward the end of the 19^th Century. By the 1930s, -ald was the sound of an All-American boy.

The trend was huge, but the number of different names involved was surprisingly small. The graph shows three main stripes representing the individual names Ronald, Donald and Gerald. Those three accounted for 98% of all -ald names. They were the trend.

New-Look Trends

75 years later, a new three-letter ending was the toast of the town for boys: -den as in Aiden, Jayden and Brayden. In the first decades of the new millennium, the -den names reached nearly the same popularity heights as the -ald generations earlier. But that’s where the similarities end.

Where the -ald graph told a story of three hit names, the -den graph is an aggregation of hundreds of less common names. In fact, the true degree of fragmentation is even more extreme than you can see. The number of different -den names was so great that they exceeded the number of lines the graphing program could process. I had to combine the 146 least common -den names into a single stripe to make the graph work.

The -den wave was a phenomenon of pure sound, bigger than any specific set of names. Remember Michael and David, and how unlikely “Pichael” and “Zavid” sounded? Well, the -den craze included “ayden” names starting with every single consonant in the alphabet, including hundreds of Paydens and Zaydens.

The -den sound also followed a faster trajectory. It took 56 years from the time the -ald names first gathered momentum for them to hit their peak. The -den names took just half that time to rise, and their decline projects to be equally swift. You can see the difference when the two curves are overlaid.

Put it all together and you have a sensitive and volatile modern naming environment. Almost any spark can ignite a new trend: not just a specific name but an idea, expressed in a multitude of creative ways. They rise fast, and if the -den names are any indication, they’ll fall just as quickly.