With Social Security, you can start taking benefits as early 62 if you’re willing to take a hit on your overall benefits. Depending on a number of factors, if you start taking Social Security payments at a reduced rate when you’re 62, your total benefit could be reduced by as much as 25%. To maximize your total Social Security benefit, you should wait until the full retirement age or later (if you’re willing to wait until 70 until you take the benefit, that’s when you’ll get the most).
The problem is that there are so many factors involved that telling someone to wait until 70 or start at 62 may not be the best idea. If you pass away before you benefits are paid out, your spouse still gets survivorship benefits so if you’re concerned about your life span, that’s no reason to start taking benefits early. (if you have a strong financial reason, as in loss of income or increase in expenses, that would be a reason to start taking benefits)