AMES, IA—Saying the findings were consistent across all demographic groups, a study published Monday by researchers at Iowa State University found that the vast majority of humans are happiest when the rest of their family is still asleep. “Nearly 90 percent of people experience their greatest feelings of delight and contentment on occasions when they wake up early and get to spend time alone in their quiet house while their spouse and children are still in bed,” said study co-author Bethany Zane, adding that 67 percent of respondents said unexpected moments of alone time during weekdays before work made them instantly more cheerful, while 78 percent said there was no greater joy than having the house to themselves for an hour or so on a Sunday morning. “Of those who linked their good spirits to being awake while their loved ones slept, roughly half said their happiness chiefly derived from the ability to read a book in peace for once, while approximately another third attributed it to the luxury of enjoying breakfast without having to prepare food for someone else. Those remaining said they were just happy they didn’t have to talk to anyone.” The study also found that the second-greatest source of happiness for the majority of humans is being awake at night after the rest of their family has gone to bed.