Author’s Note

I wrote this book of short, informal essays to intrigue and entertain you. It’s not a full tutorial on brains. Each essay presents a few compelling scientific nuggets about your brain and considers what they might reveal about human nature. The essays are best read in order, but you can also read them out of sequence.

As a professor, I usually include loads of scientific details in my writing, such as descriptions of studies and pointers to journal papers. For these informal essays, however, I’ve moved the full scientific references to my website, sevenandahalflessons.com.

Also, at the end of this book, you’ll find an appendix with selected scientific details. It offers a bit more depth on some essay topics, explains that certain points are still debated by scientists, and gives credit to other people for some interesting turns of phrase.

Why are there seven and a half lessons rather than eight? The opening essay tells a story of how brains evolved, but it is just a brief peek into a vast evolutionary history — hence, half a lesson. The concepts that it introduces are critical to the rest of the book.

I hope you’ll enjoy learning what one neuroscientist thinks is fascinating about your brain and how that three-pound blob between your ears makes you human. The essays don’t tell you what to think about human nature, but they do invite you to think about the kind of human you are or want to be.