It was difficult to hold Broca’s brain without wondering whether in some sense Broca was still in there—his wit, his skeptical mien, his abrupt gesticulations when he talked, his quiet and sentimental moments.

It wasn’t really a loud-mouthed, hyperactive little pig-tailed blonde that made Carl cringe. It was what I represented. While his upbringing was battered humiliation, I was spoiled, doted on, and spoon-fed by the world. I...