During a visit to a Hong Kong children’s welfare home, I met a 12-year-old girl I'll call Kylie. She had suffered a severe illness that left her blind, deaf, non-verbal, and nearly immobile, yet no identified damage was done to her brain.
The staff described her, without hesitation, as “always cheerful,” and indeed she smiled the entire time I watched her on the standing frame.
We can't objectively verify Kylie’s internal state, but her case crystallized a puzzle: if the absence of sight, hearing, or mobility doesn't preclude happiness, and neither wealth nor fame can guarantee it, then what truly determines our level of happiness?
Brickman & Campbell (1971) called this puzzle the Hedonic Treadmill: as a person experiences a positive emotional event, expectations and desires rise in tandem which cancels their net long-term impact, resulting in no permanent gain in happiness.
So no matter how hard one tries to gain in happiness, one will remain in the same place.
Later studies show the same homeostasis after negative shocks: people recover from bereavement, disability, or loss, drifting back towards a stable baseline level of happiness. The baseline level may be identified at different points among individuals (such as neutral or positive), but is stubbornly stable within them.
The implication is disheartening. If no action durably lifts well-being, then our daily efforts seem to generate motion without progress.
We can break the treadmill, downward: substance abuse, chronic depression, or traumatic brain injury can lower one's baseline for years. The biological mechanisms involve long-term changes in dopaminergic and serotonergic signalling, glucocorticoid cascades, and possibly neuroinflammation—none pleasant.
But the platform can surely be raised as well, right? Some empirical literature says yes: subjective well-being is correlated to durable improvements in happiness baseline, suggesting interventions such as:
The list goes on, and initially it made me hopeful. It painted a path towards a richer, more fulfilling life. But eventually, it felt like something was missing. I haven't found any particular novel hacks, and any sensible person would have known and practiced them already.
Then I realized. They are not hacks to the treadmill; they are user manuals. They tell you how use the treadmill without wearing it down, not how to transcend it. For people living below their baseline, these strategies can restore functionality. But for those already running well, there may be no higher gear.
Transhumanist proposals, such as direct neural reward modulation, gene editing, wire-heading done right, so far remain speculative and practically uncertain. However, reflecting on how such interventions would practically function brought back memories of Economics 101, and certain fundamental principles that has governed all intelligent agents.
Economics offers a clarifying lens through Diminishing Marginal Utility (DMU): the nth unit of any good is always worth more than the (n + 1)th. Concave utility curves imply plateaus; consume enough cake and the next slice is first dull, then nauseating. Apparent exceptions like threshold goods are local quirks on the curve, not global violations. And I’ve encountered articles on DMU exceptions being completely mistaken on the definition of utility. Thus far, all intelligent beings have always exhibited DMU, which acts as the restoring force returning happiness level to baseline.
Physical production obeys the analogous principle: Diminishing Marginal Return (DMR). Each extra unit of resource, such as labour or capital yields less output once easy gains are exhausted. In finite reality, production curves eventually turn flat or negative, creating a treadmill effect for any real-world system[1]. The hedonic treadmill simply expresses DMR in qualia-space. Hence, the stickiness of our happiness baseline is unsurprising.
Will DMU/DMR constrain AGIs with a treadmill? Likely to some extent, especially if we designed them carefully. The utility and production curves will flatten somewhere, though that “somewhere” may be beyond humanity’s comfort zone. Fast-take-off scenarios could still occur. DMR is a brake, not a wall, but still a brake.
As humans, we'll likely remain bound to our hedonic treadmills for a long time. Though if your own treadmill is intact, i.e. free from affective disorders or addiction and you are practicing fundamental well-being habits, you are already experiencing the highest sustainable average happiness humans can currently achieve. Maintenance, not optimisation, is the rational priority.
Cherish the plateau. For now, it is our summit.