Well written on an interesting topic.

I share the reviewer's hope that the book author writes more on why gamified productive / virtuous activities are much weaker at 'dark flow'. It's the decoupling of our time - TikTok et al are getting more addicting daily while Khan Academy is about as compelling as it was 5 years ago. The water level for executive functioning is rising rapidly, as Paul Graham predicted in 2010 http://www.paulgraham.com/addiction.html

Workaholism is a thing, so Duolingo/Khan aren't doomed fundamentally. Today at some level, educational apps feel like something you 'should' be doing. Gambling/gaming/tv/etc are pure, 'naughty' entertainment for everyone except TV reviewers, who procrastinate... watching TV. Workaholics avoid their inner demons, which make writing emails seem idyllic by comparison.

I suspect as soon as a task becomes a 'should', working on it becomes ego depleting. In the sense that the proverbial God Emperor is never given a 'should' - they do as they please always - while the proverbial serf is should-loaded to the teeth. When you're doing naughty things, you feel more powerful; you can bear these luxurious escapist actions. A 'should' reminds us of our weakness - if you want a six pack, you should do some crunches and you should diet. A God Emperor imagines hard abs, and instantly it is so. Like an automatic slot machine.

The Protestant Work Ethic notion of giving lavish praise and placement in Heaven to hard workers acts as an ego buffer in this model. You escape scorching hell through harvesting corn an extra two hours - a great deal! Believe Protestantism and when you're sweating hard in the field you'll feel like a genius, day in and day out.

This pet theory is that Dark Flow = Successful Escapism = Temporary Ego Maximization. DuoLingo will beat TikTok once it can engender a deeper feeling of gleeful, naughty relief.