Human behavior encompasses a vast spectrum, ranging from the selflessness of saints to the extreme violence of sadists, a complexity that eludes explanation by any single disciplinary framework. This paper proposes a six-layer integrative model that unifies fragmented knowledge from neuroscience, evolutionary psychology, emotion theory, cognitive science, metacognition research, and existential psychology into a parameterizable computational framework. The model posits that all behavior originates from a fundamental "pleasure-seeking and pain-avoidance" mechanism (Layer 0: Biological Hardware), which is instantiated through gene expression, neurotransmitters, brain structures, and hormones. This motivational engine drives 21 basic instincts pre-installed by evolution (Layer 1: Instincts) to address challenges related to survival, reproduction, hierarchy, group dynamics, cognition, and morality. These instinctual drives are dynamically modulated by 8 basic emotions (Layer 2: Emotions), which act as the "dashboard" and "accelerator/brake" for the instincts. The resulting impulses are subsequently interpreted, weighted, and rationalized by the cognitive layer (Layer 3: Cognition), composed of belief systems, attributional styles, value weights, cognitive distortions, and cognitive complexity. This entire process is overseen by the metacognitive layer (Layer 4: Metacognition), a second-order feedback system comprising five quantifiable dimensions (awareness, evaluation bias, control efficacy, reflection habits, metacognitive knowledge) responsible for monitoring and regulating lower-level processes. Finally, the meaning system (Layer 5: Meaning) serves as the ultimate arbiter, providing an ultimate value vector and redefining the coordinate system of "pleasure" and "pain," enabling individuals to transcend immediate gratification in pursuit of long-term existential meaning. This paper elaborates on the model's dynamic characteristics, including bottom-up drives, top-down regulation, and learning mechanisms operating across multiple time scales (from real-time neuro-hormonal changes to long-term epigenetic and neuroplastic remodeling). The model's explanatory power is demonstrated through in-depth analyses of four extreme cases (the sadist, the life-lover, the infanticidal parent, and the masochist). This six-layer model offers a unified language for understanding the full spectrum of human nature, provides a blueprint for computational social simulations, and opens new avenues for empirical research in fields such as clinical, developmental, and social psychology.
Wang Yi (Thu,) studied this question.