The proportion of people aged over 65 has increased from 15% to 22% between 1991 and 2020. Eestimates for Germany regarding the proportion of the population for the increase of older people (at least 65 years) are currently 22% and are expected to reach 34% by 2060 (Federal Statistical Office of Germany 2021b).) (Federal Statistical Office of Germany 2021a). In the USA, the proportion of the population has also increased during the same period from 12.7% to 16.2% (World Bank 2019). This demographic change in Western societies brings the scientific (and political) examination of age(ing) increasingly into the focus of various disciplines such as sociology, biology, medicine, psychology, educational science, etc. Gerontology is a distinct multidisciplinary field of research in this canon, which is interested in the empirical investigation of age-related questions (van Dyk 2015, p. 7).