Jeffrey Gray

British neuropsychologist who developed the theory of the Behavioral Inhibition System (BIS) — identifying the neural circuit that activates when organisms encounter punishment, non-reward, novelty, or conflicting goals — providing the biological foundation for anxiety theory.

Proposed that anxiety is the output of the BIS — a system that stops ongoing behavior, increases arousal and attention, and orients the organism toward the threatening stimulus when it detects a mismatch between expected and actual events — providing Peterson with the neurobiological grounding for his chaos/order model.