How Scratch-and-Sniff Books Encode Smell Across Development

Scratch-and-sniff books combine olfactory cues with textual and visual narratives thus offering multisensory reading experiences. Despite their popularity since their emergence in the 1970s, these books have received little scholarly attention, particularly regarding their cognitive and developmental relevance. This paper presents a mixed-methods analysis of 334 scratch-and-sniff books, investigating how smell content varies by target age, conceptual complexity, and linguistic framing. Quantitative analyses reveal systematic differences in smell types, labelling strategies, and descriptive complexity depending on target readership age. Books targeted at younger readers tend to feature simple, explicitly labelled smells (e.g., "apple", "chocolate"), while those books targeting an older audience rely more on implicit references, humour, and/or socially transgressive smells (e.g., "fart", "smelly feet"). Qualitative readings show how olfactory cues are embedded in broader narrative structures that support inferencing, emotional resonance, and social norm acquisition. We argue that scratch-and-sniff books may be designed to use smell not only with the intention to entertain, but also to prompt crossmodal mapping, encourage inferential reasoning, and scaffold early engagements with sensory and social meaning. These findings indicate that scratch-and-sniff books systematically adapt their olfactory content and linguistic framing to developmental stages, suggesting that smell may serve not only to entertain, but also to scaffold emerging sensory, cognitive, and social capacities in early reading.