"My son, be wise, and make my heart glad," -- Proverbs 27:11 (NKJV)
Mastermind doesn't quite fit into any category that I know. It's not a book about science. If it were, there would be a lot more science in it. It's not a self-help book. If it were, there would be a great many tools to apply along with exercises. It's not a pop culture book. If it were, the references would be to some character or person more contemporary than Sherlock Holmes and Dr. Watson.
To me, the book came closest to being that most wonderful of all books, a sincere homage designed to bring new reasons to appreciate a writer and his creations. Maria Konnikova uses scientific research and simple observations about psychology to validate the approaches used by Sir Arthur Conan Doyle in writing the Holmes books and stories. Reading Mastermind made me want to re-read the whole series again. Fortunately, I have a complete set in my library.
So if you can't get enough of Sherlock Holmes and his methods, Mastermind will be a source of new reasons to enjoy those fictional outings. If, instead, you want to learn about how to make better decisions, you'll find better books elsewhere.
In recent years I've found that books about Sherlock Holmes and Sir Arthur Conan Doyle tend to be on the debunking side. I enjoyed reading a book like this one that might have been written by a zealous defense attorney with good communication skills.