Quantified self

Definition

The Quantified Self is the practice of self-tracking: using technology to record data about one's own body, behavior, and environment in order to learn something from it. The movement's motto, coined by its founders, is "self-knowledge through numbers."

Origin

The term and the community were established by Gary Wolf and Kevin Kelly, both of Wired, who started the Quantified Self blog in 2007 and convened the first meetup in 2008 in the San Francisco Bay Area. Local meetup groups spread internationally, organized around a distinctive format: the show-and-tell talk, in which a participant answers three questions — what did you do, how did you do it, and what did you learn.

That format is the movement's most underrated feature. It is a genre for reporting single-subject experiments, and it enforces honesty about method in a way that product marketing does not.

Quantified self describes a method of recursive self-reflection through making visible what was formerly invisible through the normal observation of everyday life. A cybernetic feedback loop where one can see the effect of something over a long period of time by taking measurements at an interval.

Known versions of a quantified self are Feltron's Annual report, personal wearable pedometers, Aaron Parecki's 3.5 years of GPS data, and Will Wright's SIMs game.

Tracked Data

Steps, heart rate, heart rate variability, sleep stages, weight, body composition, blood glucose, blood pressure, mood, medication, caffeine and alcohol, food intake, location, screen time, keystrokes, productivity, menstrual cycle, air quality, and — in the movement's more committed corners — continuous glucose monitoring by people without diabetes, and DIY blood panels.

Key Ideas

• n-of-1 experimentation. Population studies report averages, and an average may describe nobody. Tracking your own responses over time can identify effects specific to you that a trial would never surface. The corresponding weakness is that a single subject with no control and no blinding is highly vulnerable to placebo, regression to the mean, and the observer effect of tracking itself.
• Instrumenting the invisible. Much of what is tracked was previously unavailable at any price — continuous heart rhythm, sleep architecture, glucose response to a specific meal. The interesting cases are those where the measurement changes the behavior before any analysis happens.
• From self-knowledge to compliance. The movement began as a hobbyist and hacker practice, with participants building their own tools and owning their data. Its commercialization shifted the emphasis: consumer wearables largely report a score rather than data, and the same instrumentation appears in insurance programs, corporate wellness schemes, and employment contexts, where the tracking is no longer voluntary in any meaningful sense.

Criticism

Three lines of objection recur. The first is validity: consumer devices are frequently inaccurate for the quantities they claim to measure, particularly sleep staging and energy expenditure, and are rarely validated publicly. The second is that quantification narrows attention to what is measurable, so that unmeasured but important things — relationships, meaning, rest that does not register as sleep — are implicitly devalued. The third is political: data generated by a body is generated for someone, and the asymmetry between what the person sees and what the platform retains is the whole business model. Deborah Lupton's work distinguishes self-tracking that is private, pushed, communal, imposed and exploited, and notes that the last three are now the common cases.

Relevance to Cyborg Anthropology

Self-tracking is the point at which a person becomes both the instrument and the subject of measurement — and where a device begins participating in the regulation of a body, which is the original criterion in Clynes and Kline's definition of a cyborg. It also connects directly to reality mining and to the optimization of ordinary life.

Related Reading

• Cyborg
• Sandy Pentland
• Soylent
• Timothy Ferriss
• Implant
• Extended Self