The reason grandparents get up at dawn and teenagers stay awake into the wee hours might be related to how ancient humans guarded their settlements, New Scientist reports. For 20 days, anthropologists monitored sleep patterns in the Hadza, hunter-gatherers who live in groups of about 30 individuals in modern-day Tanzania.
The exact causes as to why walking inspire creativity are still unknown, though this study puts forward a number of potential reasons. Most important, the authors conclude, is that we move. Data might be mixed but anecdotes and test scores are not.