This preprint proposes a systems-level framework for human personal identity based on a finite set of interacting biological systems. Rather than defining identity through static traits such as fingerprints, facial morphology, or DNA alone, the framework argues that individuality emerges from the long-term coupling of five autonomous systems: the neurophysiological system, the cardio-autonomic system, the biochemical–metabolic system, the gut microbiome, and the adaptive immune system. Each system is evaluated according to four criteria: generative autonomy, inter-individual variability, temporal persistence, and empirical measurability. The review further distinguishes true generators of identity from measurement modalities, analytical descriptors, and behavioral outputs. The article concludes that human identity is best understood as a multi-layer dynamical signature generated by the persistent interaction of these five biological systems.
Hussein Hadi Abbas (Tue,) studied this question.