Why do humans have language and other animals apparently don’t? It’s one of the most enduring questions in the study of mind and communication. Across all cultures, humans use richly expressive languages built on complex structures, which let us talk about the past, the future, imaginary worlds, moral dilemmas and mathematical truths. No other species does this.

Yet we are fascinated by the idea that animals might be more similar to us than it seems. We delight in the possibility that dolphins tell stories or that apes can ponder the future. We are social and thinking creatures, and we love to see our reflection in others. That deep desire may have influenced the study of animal cognition.