How Don and Betty dropped off the radar

Betty and Donald are the baby names that have fallen farthest in popularity since the time of the 1940 census, according to a new study.

Both ranked among the 10 most popular US baby names in 1940, finds the study conducted by family history website to mark the release of the 1940 Census records on April 2.

Today they top the endangered list – yet they are also both the names of the moment because they are given to lead characters in hit TV series Mad Men.

Donald was the ninth most popular name for American boys born in 1940 but now ranks just 377th.

Betty was the fifth most popular name for American girls born the same year but no longer even makes the top 1,000.

Baby names are like period pieces”, says Josh Taylor, a leading genealogist and spokesperson for “Some recall a particular era, which can make them useful clues for researching family history.

“Indeed, you can sometimes guess roughly when someone was born simply by their first name. In such cases, names can be to genealogy what carbon-dating is to archaeology.”

Carol, Shirley and Ronald are other names from the 1940 top ten now on the endangered list. researchers trawled the records of the US Social Security Administration, which has recorded baby names, based on Social Security applications for births, since 1879.

At the time of the 1940 Census, Mary and James topped the US rankings for baby names.

Betty has fallen farther and faster from favour than any other name, male or female. Ranked the fifth most popular girl’s name in 1940, it was the first of the 1940 top 10 to drop entirely from the top 1,000, which it did in 1997. Carol followed in 2007 and Shirley in 2009.

The high profile of both Donald Trump and Mad Men’s Don Draper in recent years has failed to stem the declining popularity of their first name. Its downward spiral has continued every year this millennium.