Overview
State of Mind is the control in Apple's Health app for logging how you feel — a momentary emotion, or a mood for the whole day. It runs on Apple Watch, iPhone, and iPad, and shipped with iOS 17 and watchOS 10 in 2023.
Moods and emotions are subjective. The design decision was to draw them exactly anyway — a fixed petal count for each state, so the same state of mind always draws the same shape.
One gesture carries the watch and the phone: a slider you drag, a crown you turn, both moving through the same continuous range. The iPad inherits it, so it is learned once and known everywhere. A log you repeat is the only kind that becomes data — the gesture had to cost almost nothing, because the value is in the hundredth entry, not the first.
A state is a position on the axis, not a pick from a set. The count is what the form returns to; the amplitude is how far it has travelled from rest.
Color and shape are two continuums, and both carry the state. The hue slides along the ramp while the form opens and closes — a circle at neutral, drawn to points one way, in bloom the other — so it holds with no color at all.
The equation is exact, and the person never meets it. A radius that changes with angle carries the count, the depth and the shape at once — the precision stays in the system, and what reaches the hand is a shape that moves. It was derived with the engineering team rather than handed to them: more than forty candidate settings were built and rejected before these seven closed.
Only after the shape is set does the app offer words for it, and they are optional. Naming it is the hard part of logging one — by the time the question arrives, it is already answered. The vocabulary came out of work with the health and medical team: which words appear, and where they sit on the scale, is a clinical question rather than a design one.
The control had to run on hardware five years old the day it shipped — Apple Watch Series 4, iPhone XS, and both generations of the SE.
The same control was mapped to the one axis a headset already has: unpleasant near, pleasant far, the form holding a constant eight degrees so scale carries nothing and depth does the reading. Apple never shipped State of Mind on Vision Pro — this is a concept, built to test whether the system survives a change of hardware class. Open the prototype →
