What you go by
Bill and William are the same name. So are Mike and Michael, Tom and Thomas, Peggy and Margaret. The people carrying them share an era, a heritage and a family. The only difference is which form they chose. It turns out to predict their politics.
In 84 of 113 pairs we can measure, the nickname leans more conservative than the formal name.
The pattern first showed up somewhere unexpected: in the voting records of Congress. Among members born since 1920, every formal-versus-nickname pair ran the same way. Tom voted to the right of Thomas. Mike to the right of Michael. Tim to the right of Timothy. With only a few hundred legislators it could have been chance, so we tested it against 1.3 million North Carolina voters, where it held in 74% of pairs.
Nobody knows exactly why. Formality tracks class, region and profession, and all three track politics. But the effect survives controls for age, sex and race, which is more than can be said for most of what a name appears to tell you.
Every pair, most conservative shift first
Shift is the nickname’s ideology score minus the formal name’s, so a positive number means the short form is the more conservative one. Pairs need 500 contributors on each side.