I distinguish between two kinds of self-experimentation part of your job (the usual kind) or self-help (what I do) and it’s easy to put each of the examples in the article into one pile or the other. However, I think that if you go far enough into the future and look back, you will see three varieties:
1. Professional. Self-experimentation done as part of your job (e.g., doctor). A dentist testing a new anesthetic, for example. All famous examples are in this category.
2. Self-help. Self-experimentation done to improve your own life. Done by non-professionals. I call this personal science.
3. Combination of the two. A professional combines job skills and self-help. This is what I did. My job (experimental psychologist) gave my self-experimentation (about weight loss, sleep, mood, and health, all common self-help topics) a considerable boost.
Professionals (Category 1) have skills and resources. The self-helpers, the non-professionals (Category 2) have freedom and (greater) motivation. People in Category 3 have all four. To summarize this paper in three words, that really helps. Please imagine the Venn diagram one circle (”Professional”), another circle (”Self-Help”), and area of overlap (”Me”).