Morning lark or night owl?

Your chronotype is your natural tendency to sleep and feel alert at certain times — lark, owl, or in between. It's largely genetic and shifts with age (teens skew late, older adults early).

Only to a limited degree. Consistent light and bedtimes can shift your schedule gradually, but the underlying type is mostly genetic — easier to work with than against.

Not inherently. The harm comes from forcing a late type onto an early schedule, building chronic sleep debt. Aligning sleep to your rhythm is healthier than fighting it.