I think studies like this are a real shame. The topic is interesting, but the method and the analysis are terribly poor. It is quite disingenuous to use "Across the Life Span" in the title of the paper when no longitudinal data was collected. Also, "smoothing" and "dampening noise" are quite worrying to see. The process of making data fit your statistical models or tools like this is another form of inaccuracy (or dishonesty).