If you’re wondering when old age is going to start officially, then there’s arguably no one better to ask than those already living their best elderly lives. Growing old is a natural part of human existence, and yet, it’s not exactly clear when middle age ends and old age begins. When does old age start?In a newly published paper in the Psychology and Aging journal, researchers from the United States and Germany analyzed data from the German Ageing Survey. With over 14,000 people born between 1911 and 1974, the team asked: “At what age would you describe someone as old?” Interestingly, those i…