“Classical scientific definitions of intelligence use humans as a yardstick by which all other species are measured. According to these anthropocentric definitions, humans are always at the top of the intelligence rankings, followed by animals that look like us (chimpanzees, bonobos, etc.), followed again by other “higher” animals, and onward and downward in a league table—a great chain of intelligence drawn up by the ancient Greeks, which persist one way or another to this day. Because these organisms don’t look like us or outwardly behave like us—or have brains—they have traditionally been allocated a position somewhere at the bottom of the scale. Too often, they are thought of as the inert backdrop to animal life. Yet many are capable of sophisticated behaviors that prompt us to think in new ways about what it means for organisms to “solve problems,” “communicate,” “make decisions,” “learn,” and “remember.” As we do so, some of the vexed hierarchies that underpin modern thought start to soften. As they soften, our ruinous attitudes toward the more-than-human world may start to change.”