A 2015 study1 highlighted that frequency effects are ubiquitous for infants whether they are learning cognitive tasks such as facial recognition or whether they are learning language skills. Frequency effects were found when infants/children were learning single words, simple syntactic constructions, and with more advanced syntax, as well as in other areas of language learning. The authors1 even stated that, “we propose that frequency effects are ubiquitous in every domain of child language acquisition …” (p. 241).
An example of a frequency effect is that the first words learned by babies are generally high-frequency words. In other words, when other factors are about the same, babies learn words that they have heard more frequently before they learn less frequent words. Infants generally take many months to learn to understand their first words, then once they understand around 50 words or so, they go through a phase that was called “fast mapping” where they learn new words at a very fast pace. In our videos we have some very high-frequency words such as clap, wave, and mouth because a high level of frequency is generally needed to learn the first words, whether these words are spoken or written in the native language or in non-native languages.
An example of the long-term influence of a well-known frequency effect in language learning is that children who hear more words in the first three years of life have greater vocabularies at age 11 than children who hear fewer words2.
1 Ambridge, B., Kidd, E. Rowland, C. F., & Theakston, A. L., (2015). The ubiquity of frequency effects in first language acquisition. Journal of Child Language, 42, pp 239-273.
2 Hart, B. & Risley, T., (1995). Meaningful Differences in Everyday Parenting and Intellectual Development in Young American Children. Baltimore: Brookes.