In this fresh and often playful interdisciplinary study, Lisa Zunshine presents a fluid discussion of how key concepts from cognitive science complicate our cultural interpretations of "strange" literary phenomena. From Short Circuit to I, Robot, from The Parent Trap to Big Business, fantastic tales of rebellious robots, animated artifacts, and twins mistaken for each other are a permanent fixture in popular culture and have been since antiquity. Why do these strange concepts captivate the human imagination so thoroughly? Zunshine explores how cognitive science, specifically its ideas of essentialism and functionalism, combined with historical and cultural analysis, can help us understand why we find such literary phenomena so fascinating. Drawing from research by such cognitive evolutionary anthropologists and psychologists as Scott Atran, Paul Bloom, Pascal Boyer, and Susan A. Gelman, Zunshine examines the cognitive origins of the distinction between essence and function and how unexpected tensions between these two concepts are brought into play in fictional narratives. Discussing motifs of confused identity and of twins in drama, science fiction's use of robots, cyborgs, and androids, and nonsense poetry and surrealist art, she reveals the range and power of key concepts from science in literary interpretation and provides insight into how cognitive-evolutionary research on essentialism can be used to study fiction as well as everyday strange concepts.