Have you watched the heartbreaking viral video of Mama, a dying elderly chimpanzee, as she says goodbye to a scientist who was part of her life for many years? (If you haven’t seen it, you should — just lay in a supply of Kleenex first.) The Dutch-born primatologist Frans de Waal believes that Mama’s tender caresses show that animal emotions are the same as our own.

“We like to see ourselves as special, but whatever the difference between humans and animals may be, it is unlikely to be found in the emotional domain,” he wrote in a Times Op-Ed. His new book, “Mama’s Last Hug: Animal Emotions and What They Tell Us About Ourselves,” enters the list at No. 4.

Image Frans de Waal Credit... Catherine Marin

“I think animal intelligence and emotions are completely intertwined,” de Waal said recently on the Times Book Review podcast. “Also in humans, I think, you cannot separate the two. You can barely think without emotions, and you can barely have emotions if there’s not some cognition involved.” He explained, “Emotions are bodily states. When you get emotional, your heart rate goes up, your blood pressure increases. … These changes are very much the same in humans and animals. For example, we say we get ‘cold feet’ when we’re afraid, and that’s literally true, we’ve tested it. It’s true for rats, too — they get cold feet, and their tails get cold, when they are scared. What fear does is draw the blood from the extremities.”