The Ratio Hypothesis

The dominant clinical account of Attention Deficit Hyperactivity Disorder frames attentional dysregulation as a neurochemical deficit: dopaminergic underactivation at task closure, correctable by pharmacological intervention that normalises motivational salience. This paper proposes a reframe. The Ratio Hypothesis holds that the behavioural profile attributed to ADHD, including attentional variability, hyperactivity, impulsivity, and the apparent paradox of hyperfocus, is better understood as the output of a cognitively coherent, high-functioning discovery-optimised system in structural mismatch with environments designed around a different motivational architecture. The problem is not that the discovery-reward signal is too weak to motivate task engagement. The problem is that it is too strong to allow closure-reward to compete. The signal is not deficient. The ratio is extreme. This reframe is derived from the Feegle Architecture (Temte 2026a), which provides the mechanistic substrate: parallel multi-modal search, a self-exciting discovery-reward reactor, and a process-indexed stopping criterion that responds to discovery potential per task phase rather than to external task importance. The reframe generates specific predictions distinguishable from existing accounts, resolves the hyperfocus paradox that has challenged the deficit model since its clinical identification, and implies a critique of DSM diagnostic methodology, via the Exceltric thinking framework (Temte 2025d), as a case of measurement apparatus colonising the phenomenon. The paper also proposes a renamed diagnostic category, Attention-Driven Hyperfocus Drive (ADHFD, acronym preserved with revised expansion), as a positive characterisation of the cognitive architecture.