The effect of phonological complexity on the order in which words are acquired in early childhood

During the second year of life, children acquire words and expand their receptive and expressive vocabularies at a rapid pace. At this age, toddlers’ phonological abilities are also developing rapidly. The current study investigated the effect of phonological complexity of words on the order in which they are acquired, receptively and expressively. Data were collected from Hebrew-speaking parents of 881 typically developing toddlers: 417 girls and 464 boys, aged 1;0 to 2;0 years old. Parents reported on their child’s receptive and expressive vocabularies by completing a computerized version of the Hebrew adaptation of the MacArthur-Bates Communicative Development Inventories. Phonological complexity scores of the target words were calculated using the Phonological Mean Length of Utterances measure. The proportion of children who were reported to understand and produce each word at each age was calculated. Results showed that phonological complexity affected the acquisition of word comprehension and word production. Words that are less phonologically complex were acquired earlier, representing a process of subconscious selection of words that are easier to produce.