The discrepancy between low, middle, and high socio-economic groups' vocabulary proficiency by age 3 is tremendous⎯estimated at a 30 million-word gap between households where children have extensive language exposure and those with minimal language exposure, according to Risley and Hart's landmark 2006 study. This phenomenon has been referred to as "the early catastrophe," which reflects the fact that this premature gap in knowledge has wide-ranging consequences and grows exponentially as students advance through Grades K-12. Additionally, research has found that students with a large lexicon can learn and subsume new words much more quickly and easily, while students with smaller lexicons acquire new vocabulary more slowly. Words beget new words, and increasing students' vocabulary knowledge of word meaning allows for the widening of vocabulary-learning trajectories. Conversely, students with low or deficient vocabulary skills will have an increasingly harder time catching up to their peers. This is a well-documented example of the "rich get richer, poor get poorer phenomenon," or the "Matthew effect" (coined by Stanovich).