English Vocabulary Size in Adults and the Link with Educational Attainment

Abstract

AbstractModern estimates of English native speaker vocabulary size have concentrated on acquisition in childhood (e.g. Biemiller & Slonim, 2001) and among undergraduates (e.g. Milton & Treffers-Daller, 2013). There seems to be an assumption that vocabulary size is pretty stable in adults and that the estimates for undergraduates are likely to be applicable to the broader population, at least until age related decline begins sometime after the age of about 60 (Burke & MacKay, 1997). The study reported in this paper examines a cross-section of adults aged from 20 to over 60, and from graduate and non-graduate populations. The results suggest that the graduate population has a marginally larger vocabulary size than the non-graduate population and it is speculated that the difference is probably too small, and the vocabulary sizes too large, to drive educational differences. The graduate population also differs from the non-graduate In the graduate population vocabulary size appears to continue to grow with age, but while vocabulary size scores vary in the non-graduate population, the differences noted are not statistically significant after the age of 30.