Socioeconomic status
One of the studies Fernald focused on was the effect of socioeconomic status on language processing skills and vocabulary. Socioeconomic status in this study were based upon the education level of each parents, occupation of each parent, and income. She focused on children between the ages of eighteen months to twenty-four months. In the beginning of her study, she found that at the start the children did not seem to have a difference in skills and vocabulary, but at twenty-four months they had an approximate six month gap. Her research contributed to the debates during the Civil rights movement, when the question was raised of if there was truly inequalities in education between Black and White schools. In her research she found that socioeconomic status does affect the way that children develop language, these factors include: childcare and amount of time spent with the child. In Fernald's research, she found that socioeconomic status does matter, but the quantity and quality of interactions with children. Fernald's research contributed to language acquisition and also helped illustrate that there are many factors that go into how a child develops their repertoire in vocabulary.