What changed your life?

Reading the chart

Each dot is one item. The further right, the more people rated it. The higher up, the more likely someone who tried it gives the answer you picked above the chart.

Why one vote can't top the chart

Every estimate starts from an average and moves as votes come in, so a few enthusiastic votes can't carry an item far. Items also need at least 30 answers to show up on the chart and in the ranking. Faded dots still lean mostly on survey data. Solid ones lean on votes from this site.

Where the data comes from

Before anyone voted here, I seeded the chart with public data:

• Nootroflix (2022), a nootropics recommender with about 29,000 ratings. Its dataset also includes the 2016 SlateStarCodex nootropics survey (about 6,700 ratings).
• The 2014 SlateStarCodex nootropics survey.
• The SSRI, therapy and meditation questions from the SlateStarCodex 2019 survey, and the diet and NoFap questions from the 2020 survey.
• The 2012 US National Health Interview Survey, for chiropractic, massage, acupuncture, meditation, yoga and tai chi.

I converted their ratings to the five answers used here, and a 10 out of 10 counts as life-changing. Some surveys only asked how helpful something was: their top answer counts as a big help, and they don't count toward the life-changing estimate. An item covered only by those surveys joins that chart once someone votes on it here.

Every estimate starts from the raw survey answers. When an item has only a few answers, they're pulled toward its category's average.

Why items aren't fully comparable yet

The survey data comes from different years, communities and questions. Nootropics were rated by nootropics enthusiasts on a 0 to 10 scale. Therapies, meditation and diets were rated by SlateStarCodex readers and by US adults who chose those treatments, and some of those surveys had no “life-changing” answer. Most habits, books and gear have no survey data at all. So when two items or groups sit apart on the chart, part of the gap comes from who was asked and how, not only from the items themselves.

That's why survey data never counts as more than 30 votes in an item's estimate, however many ratings it has. Votes on this site all answer the same question, so as they come in they outweigh the surveys and the chart becomes a fair comparison. Vote counts still include every survey rating, so you can see how much data sits behind each item, and each item's page lists the surveys it draws on.

What this is and isn't

Everyone here chose to answer and describes their own experience. Treat the chart as a list of things worth reading about, not as proof that they work.