“…Taking the opposite view, this research maintains that ‘inaccuracy’, i.e., the difference between CA and BA, is a repercussion of individual variations in longevity as well as individual differences in the onset and variations in the aging processes due to genetic, epigenetic, and environmental conditions (Bae et al, ; Belsky et al, ; Cho, Park, & Lim, ; de Rooij & Roseboom, ; Levine, ). Indeed, research in living populations found the estimated standard deviation of the difference between CA and BA varies between three and 10 years (Belsky et al, ; Hochschild, ; Klemera & Doubal, ), and because the health of individuals is highly heterogeneous, as is the rate of aging, discordances between BA and CA can take place from a young age (Belsky et al, ; Molinari, Gasser, & Largo, ; Wiweko et al, ) not just among older individuals as is often assumed.…”