A quip that charms a new user becomes noise to the one who has seen it fifty times

What it is

The same personality expression is character to a new user, background noise to an experienced one, and irritation later still. Expression intensity should therefore decay with familiarity: in the early period strong expression attracts — a distinct voice, full-bodied motion temperament, a greeted, pronoun-using welcome; as usage deepens, the same expression carries less information while paying the same attentional bill. Habituation here acts as a general decay law for expression intensity: once habituated, expression must yield — not by deleting the personality, but by stepping its intensity down to a tier that matches familiarity.

Why it happens

The mechanism is familiarity rewriting attention allocation, on three layers. First, novelty decay: attention privileges the unpredictable; the information an expression carries on first appearance ("this product talks to me in this voice") is spent through repetition, and the predictable degrades from information into background — once attention withdraws, only the cost remains: reading time still spent, visual flow still interrupted. Second, falling tolerance: being amused depends on surprise, and the Nth appearance of the same style is not merely unsurprising — the repetition itself starts to read as deliberate, "it's performing again"; tolerance declines monotonically with exposure. Third, the relationship stage changes the need: new users need personality as a fast proxy for trust ("this product has a temper, a stance, someone responsible behind it"), while experienced users have already built trust from usage experience — the proxy's job is done, and sustaining high expression beyond that is self-expression. This decay law is broader than the death of a joke: a specific bit repeated verbatim is the steepest instance of it; non-humorous expression — greetings, motion temperament, pronoun density — follows the same direction on a flatter slope.

Where it stops holding

What decays is expression intensity, not the personality itself: experienced users are precisely where personality consistency pays most — lower the volume, do not change faces. The real cost of tiering lives in the same move: switching expression by familiarity means the product is a different version in front of different users, with a real risk of being read as differential treatment, plus nontrivial implementation and regression-testing cost. Decay rates also differ by channel — jokes steepest, motion next, color temperature barely at all — so there is no single "veteran mode," and one blanket tier switch cuts in the wrong place somewhere.

Applying it

• Tier expression intensity by usage depth: first week (new-user tier — greeted, pronoun-using welcome, voice allowed to take a risk, full motion temperament), first month (standard tier — voice spectrum kept, motion reined in), long term (proficient tier — shortest expression by default, personality surviving only at the baseline).
• Make the tiers configurable expression rules, not three interfaces: the same copy template with three voice parameters, the same motion with three duration and elasticity settings.
• Attach decay conditions to high-intensity expression: the welcome demotes to a plain greeting after several launches; onboarding quips switch off after the first core task is completed.
• To validate: sample in strata by usage depth and measure reading completion time, skip rate, and "annoying"-keyword frequency at the same touchpoint per stratum; negative signals higher in the veteran stratum than the novice stratum confirms the decay need — re-measure after adjusting tiers.

Related

• Same group: P1.05.1 Personality leaks through copy, motion, and color · P1.05.2 Inconsistent signals dilute personality recognition · P1.05.3 Personality must not interfere with function · P1.05.4 Personality is shown by trade-offs, not declared by adjectives · P1.05.5 Extreme moments define personality more than everyday ones · P1.05.7 Cross-channel personality is capped by its weakest link
• Nearby: P1.06.2 Humor wears out with repetition · P1.07.5 Novice and expert users evaluate the same element in opposite ways · A5.16 Habituation and notice decay
• Search terms: habituation · novelty decay · onboarding persona · expression intensity