Not even all the historians know that Pennsylvania’s Lancaster once served as the U.S. capital. Only for a day, though. Congress in flight from the British paused there for one day.

Elsewhere in this world, many people support the right hand with the left when they shake hands. For instance, in Zambia, that’s commonly seen.

Did you inherit a tendency to be easily irritated? Many people think they did. But at least one geneticist most mysteriously concludes we can blame genes for 38 percent of our irritability, but have to hang the other 62 percent on environment.