Sleep deprivation. It explains all the symptoms mentioned in the article.<p>Kids in kindergarten start early, and stay later than they have in the past with no nap period. Busy parents (both of whom are now working full-time) are lucky to get home by 7pm, so the kid(s) are generally kept up till 9&#x2F;10pm so the parents can have some time with them.<p>If parents are going to keep a 5&#x2F;6-yr old up to 9:30pm or later, then wake them up at 7:15am to get ready for school at 8:15am.... which goes till 2pm with no nap time. Well yea, sleep deprivation hurts.<p>Ask your parents, grandparents, etc when they went to sleep, when kindergarten began, how long it ran, whether it included a nap&#x2F;rest-time. Most of us got a <i>lot</i> more sleep than the kids now.<p>Edit: I agree kids need more free-play time, but that&#x27;s separate from their sleep deprivation.