The 1995 Hart & Risley Study
Meaningful Differences in the Everyday Experience of Young American Children describes the remarkable findings of Betty Hart, Ph.D., and Todd R. Risley, Ph.D. Their longitudinal study of parent-child talk in families in Kansas was conducted over a decade. A team of researchers recorded one full hour of every word spoken at home between parent and child in 42 families over a three year period, with children from seven months to 36 months of age. The team then spent six additional years typing, coding, and analyzing 30,000 pages of transcripts.
Follow-up studies by Hart and Risley of those same children at age nine showed that there was a very tight link between the academic success of a child and the number of words the child’s parents spoke to the child to age three.
Hart and Risley’s Three Key Findings:
1. The variation in children’s IQs and language abilities is relative to the amount parents speak to their children.
2. Children’s academic successes at ages nine and ten are attributable to the amount of talk they hear from birth to age three.
3. Parents of advanced children talk significantly more to their children than parents of children who are not as advanced.
- “With few exceptions, the more parents talked to their children, the faster the children’s vocabularies were growing and the higher the children’s IQ test scores at age three and later.”
- “The data revealed that the most important aspect of children’s language experience is its amount.”
- “Differences in the amount of cumulative experience children had ... were strongly linked to differences at age three in children’s rates of vocabulary growth, vocabulary use, and general accomplishments and strongly linked to differences in school performance at age nine.”
Betty Hart, Ph.D. and Todd R. Risley, Ph.D.
The Authors of Meaningful Differences in the Everyday Experience of Young American Children
In the early 1960s, Drs. Hart and Risley demonstrated the power of learning principles influencing young children. Along with a colleague, they introduced parenting techniques such as time-out. Procedures such as shaping speech and language now widely used in special education were also introduced by the team.