To describe how different variables contribute to psychological aging throughout human life, we trained DNNs on MIDUS 1 age group subsamples (25-39, 40-64, 65-75 years). These models contained the same 50 features as PsychoAge and Subjage, but their relative importance was not constant. In other words, a variable’s contribution to psychological aging was not static and its influence may vary with time.
First, we explored important variables (top-25 mean normalized PFI and DFS scores) shared by all age-group specific clocks to define the psychological aging core – features that significantly shift throughout one’s lifespan ( Table 2 ).