I picked this book at a yard sale some years ago and have just gotten around to it now. It’s a thin book, 124 pages, broken into chapters that provide different puzzles/means of cognition and intelligent ways to approach them. Memorization tips, visual skills, and whatnot.
It’s an interesting little book, with nice little tricks. However, it’s not going to put me over the cusp into the warm embrace of Mensa, mostly because the book doesn’t cure lazy. But if you’re motivated to improve your thought, it’s a quick enough read.