The paper concludes with a highlight of the need for a real time study to corroborate its argument. This being said, as is noted earlier, not all age-related variation is indicative of change in progress. Instead, it may simply be an age-graded variation. That is to say, the applicability of the apparent-time hypothesis should be confirmed by real-time evidence, which may be gathered from a longitudinal study of a population over an extended period of time.