An Individual-Level and Controlled Methodological Framework in Primate Thanatology

How primates sense, cognize, and respond to death, and are affected by it, are broad research themes within primate thanatology. When primate thanatology adopts a comparative framework, it can illuminate the diversity and evolutionary continuity of psycho-neuro-emotional responses to death and dying across primate species, including humans. Evolutionary or comparative thanatology has recently gained momentum, but it lacks methodological consistency, quantitative rigor, and coherent reporting standards. We attempt to address the lack of standardized approaches by introducing an individual-level comparative framework and employing standard ethological methods, accompanied by well-defined behavioral variables. We argue that the proposed framework can capture individual-specific responses to conspecific death and enable hypothesis-driven studies. The framework is essential to examine the large number of hypotheses that have accumulated in the field.