The ability to immediately spot and befriend any other Texan in the room.
It could be in Prague, New York, or Tokyo, wherever, and one Texan will instantly be able to locate any other Texan in the room. It might be the subtle draw of an accent or the distinctively square-toed boot on their foot, but whatever it is, it’ll be met with the twinkle of an eye and a strong handshake that all Texas mamas teach their kids.