Late sleepers are tired of being discriminated against. And science has their back.

A couple of weeks ago, I reported on the science of chronobiology, which finds we all have an internal clock that keeps us on a consistent sleep and wake cycle. But the key finding is that everyone’s clock is not the same. Most people fall in the middle, preferring to sleep around 11 pm to 7 am. But many — perhaps 40 percent of the population — don’t naturally fit in this schedule.