“Meaningful Differences in the Everyday Experience of Young American Children.” Betty Hart and Todd Risley. 1995. A review of the authors’ research on the amount of spoken language heard by young children prior to attending school at different socioeconomic levels and the ongoing impact it has on later school performance, especially reading. The amount of language, the quality of vocabulary and the type of verbal interactions prior to age three all support or inhibit future reading and school success. Intervention after age three may be insufficient to compensate for early lack of language.