The more certain you are the more power you have to convince others and convince yourself. You may want to convince them that change is needed — e.g., that a polluting factory should be shut down or cleaned up. China has a huge problem with industrial pollution, as this report describes. Children are especially at risk.
The danger to those in power posed by self-tracking — in particular, blood tests that measure lead — is shown by this quote from the report:
Even parents who were able to access [lead] testing for their children reported difficulties in obtaining the results of the tests conducted. Many parents in Yunnan and Shaanxi reported that test results from their children’s lead tests were withheld completely. Some parents in Yunnan and Shaanxi told Human Rights Watch that they never saw any test results. Others were allowed to see the results from initial testing but were prevented from seeing the results from follow-up testing.
My daily arithmetic tests (how fast can I do simple arithmetic, such as 3 + 5) have the same purpose as the lead tests: to assess the quality of the environment. If my scores get worse, it may reflect poisoning. Comparison with a blood test for lead highlights strengths and weaknesses of my arithmetic test.
1. Sensitive to many things. Can detect any bad influence on the brain, not just lead.
2. Free in the sense that the cost is zero (so long as you have a laptop).
3. Unrestrictable. No one can deny you access.
4. Fast. You get the results immediately.
5. Great sensitivity. You can test yourself as often as you want. The more tests you do the more easily you can detect a change.
6. Variability known. By looking at a graph of your data (score vs. day) you can judge the natural variability — essential for judging the importance of a deviation. With lab tests, the variability is rarely known to the person whose blood was tested or the doctor that reviews the results.
7. Measures what you care about. You care about health. Brain health is part of that. Sure, high levels of lead are bad, but what about low levels? Is there a hormetic effect? The dose-response function isn’t obvious.
1. Unconventional. A lead test is easier to understand.
2. Unspecific. If a score is bad (= if I get slower) it isn’t clear why. If you have too much lead in your blood the cause is likely to be obvious (e.g., polluting factory, lead in food).
3. Sophistication needed. The arithmetic test is sensitive to hundreds of environmental factors, I’m sure, so identifying the cause of any change inevitably requires sophistication. For example, perhaps you need to control the time of day. Another example is that you need to control/allow/adjust for practice effects.
If the Chinese parents were able to measure their children’s brain functions themselves, they might be far more outraged — and therefore far more powerful.