In my experience people lied about their ages a lot, probably for a variety of reasons. My own father lied on his marriage license because he was considerably older than my mother and didn't want her to know. Certainly the most dependable dates are going to be from baptismal and death records, but you can't rely on stated age at death on the latter--it could well be that no one knew for sure when they submitted the information. Birth dates calculated from stated age at death can only be estimates. Ages on census records may also have been submitted by others, who only guessed. I have seen birth dates differing by as much as 15 years on IGI submissions to LDS. Janet