This study investigated whether seeing iconic gestures depicting verb referents promotes two types of generalization. We taught 3-4-year-olds novel locomotion verbs. Children who saw iconic manner gestures during training generalized more verbs to novel events (first-order generalization) than children who saw interactive gestures (Exp. 1, N = 48; Exp. 2, N = 48) and path-tracing gestures (Exp. 3, N = 48). Furthermore, immediately (Exp. 1 & 3) and after one week (Exp. 2), the iconic manner gesture group outperformed the control groups in subsequent generalization trials with different novel verbs (second-order generalization), although all groups saw interactive gestures. Thus, seeing iconic gestures that depict verb referents helps children (1) generalize individual verb meanings to novel events and (2) learn more verbs from the same sub-category. People naturally produce gestures when they speak. Little is still known about the role these gestures play in children's language development. My research focused on the role of iconic gestures - gesticulations that accompany speech and illustrate what is being said. For instance, you can wiggle your index and middle fingers to depict "walking" or bring your hand to your mouth as if holding a glass to depict "drinking". Children understand these iconic gestures by age 3 and my PhD research suggested that seeing adults produce these gestures while speaking is formative for children's language learning. Studying the ways we can stimulate vocabulary growth in preschool-aged children is very important, because the vocabulary size and skills of children at this age are major predictors of later school success. During the fellowship, I will collect data from one experiment with 3-year-old children that will help us to better understand how seeing iconic gestures facilitates word learning. I will visit local nurseries to play a computer-based word learning game with 96 children. I will publish my research findings from this experiment and from my PhD dissertation in two top-tier scientific journals in developmental psychology and I will present those research findings at one international conference on cognitive development, in Budapest, Hungary. I will also develop a Leverhulme Postdoctoral Fellowship proposal that extends my PhD research. I will design a series of lab-based experiments that help us investigate how parents can use nonverbal communication (e.g. facial expressions, body language, and hand gestures) to teach their child new words. I will propose to analyse body position of the parent and child (face-to-face or side-by-side) and eye contact, touch, and gestures. Moreover, I will visit two internationally leading research groups to develop collaborative research on mother-child interactions. I will visit Simone Pika's biocognition lab, which has collected video recordings of naturalistic social interactions between chimpanzee mothers and their young living in the wild. I will also visit with Susan Goldin-Meadow's gesture lab, which has collected video recordings of naturalistic interactions between parents and children in their family homes.

A language learning task was administered to 3-4-year-old English-speaking children in their nursery or preschool. They engaged in a touch-screen game with an experimenter in which they learned novel verbs. Their understanding of verb meanings was tested in a two-alternative forced-choice test. Their answers on this verb generalization test were automatically saved to an Excel spreadsheet. The data for Experiment 3 were collected between the 28th of November 2018 and the 21st of January 2019. As in Experiments 1 and 2, the sample included 48 typically developing children (25 girls, 23 boys) between 36–50 months old (M = 43.24, SD = 4.54). An additional eight children were tested but excluded from the analysis because they pointed only to answers on the one side of the screen in test trials (N = 1), were not compliant (e.g., covered their face with their arm during the task, N = 1), did not finish all the trials (N = 1), were too old on the day of testing (N = 2), or did not meet the English language requirements (N = 3). Participants were recruited via two public nurseries and two Early Years Teaching Centers in Warwickshire (United Kingdom) and from a database of families interested in taking part in language development research with their child at the University of Warwick. The nurseries where the data for this experiment were collected partly overlapped with Experiments 1 and 2, but none of the children had participated in these previous experiments. Twelve percent of the children had a racial background other than White (8% Asian, 4% Black). There were 13 girls and 11 boys in the iconic manner gesture group and 12 girls and 12 boys in the control group. Children’s age in months did not differ between the two groups, F(1, 46) = 1.19, p = .281, nor did their gender ꭓ2(1) = 0.08, p = .773. Informed parental consent was obtained for all participants. All children were exposed to the English language for at least 70% of the time and English was the primary language spoken at home (as indicated by their caregivers). Participating nurseries received a book voucher and children who took part in the research lab received a toy and a certificate. Each child was pseudo-randomly assigned to a condition, based on their age and gender, before the experimenter met them.