Scholars have documented substantial classes of iconic vocabulary in many non-Indo-European languages. In comparison, Indo-European languages like English are assumed to be arbitrary outside of a small number of onomatopoeic words. In three experiments, we asked English speakers to rate the iconicity of words from the MacArthur- Bates Communicative Developmental Inventory. We found English—contrary to common belief—exhibits iconicity that correlates with age of acquisition and differs across lexical classes. Words judged as most iconic are learned earlier, in accord with findings that iconic words are easier to learn. We also find that adjectives and verbs are more iconic than nouns, supporting the idea that iconicity provides an extra cue in learning more difficult abstract meanings. Our results provide new evidence for a relationship between iconicity and word learning and suggest iconicity may be a more pervasive property of spoken languages than previously thought.

Past research suggests that people think about numbers in terms of multiple spatial mappings. For instance, they think of “more” as “bigger” or “higher” (e.g., Andres et al., 2008; Sell & Kaschak, 2012). Here, we investigate mental number space by looking at naturally occurring co-speech gestures. Using the TV News Archive (archive.org/details/tv), we selected a random sample of 1,320 videos containing the phrases “tiny number,” “huge number,” “high number” and “low number,” of which 314 had associated manual gestures. Our analysis shows that with “tiny number,” speakers produce pinching gestures; with “huge number,” they move their hands outward; with “high numbers,” the palms are oriented and move upward; and with “low numbers,” the palms are oriented and move downward. Speakers did not gesture systematically along the horizontal axis. This work provides new insights into how people’s spatial conceptualizations of numbers shape communicative practice in naturally occurring discourse.