fernald, marchman, and weisleder (2013) conducted a study with 48 children from diverse backgrounds ages 18–24 months old. the families were divided into low ses (socioeconomic status) and high ses. their first goal was to track developmental changes in processing efficiency in relation to vocabulary learning. their second goal was to examine difference in aspects of early language development in relation to their ses. their results showed that children at the same age from the lower-class families had lower vocabulary scores when compared to children in higher class families. fernald et al. (2013) also found that by 18 months old language processing and vocabulary disparities were already evident, and by 24 months old there was a 6-month gap between the ses groups in processing skills critical to language development. fernald et al. found fast reaction time as a child can translate into reaction time as an adult. adults who have high reaction time tend to have better memories, reasoning abilities, language skills and are better able to learn new skills (fluid intelligence). having better processing speed means having a stronger working memory, and a stronger working memory leads to a better cognitive competence. the authors express the importance of vocabulary knowledge because it sets a foundation for later literacy and language proficiency in preschool and that is predictive of academic success. implications of long term developmental trajectories. thus, the issue of the language gap and achievement gap are prevalent in our youth, which can be resolved by teaching families how to work and speak with their children.