The U.S. Census Bureau tells us the average retirement age in the United States is 62.
Social Security however, defines 62 as your early retirement age and at this age you are eligible to receive a reduced Social Security benefit.
Social Security uses the term full retirement age in place of what most of us would think of as average or normal retirement age. Full retirement age is the age at which you receive your full amount of Social Security benefits. I also think it's the same