If you follow education matters you know that the home environment in very early years are vital. One aspect of that home environment is the language infants and toddlers hear at home.
The groundbreaking work of Hart & Risley (1995; replicated by others, e.g. Huttenlocher et al, 2010) showed that socio-economic status of the parents is correlated with vast differences in the amount and complexity of language that children hear at home.
But what aspect of this speech is important? Does speech need to be directed to children? Perhaps all that’s needed is for children to be in the presence of this more complex language. After all, we know that children do not learn language via instruction; they learn it by observation.
Three studies published in the last couple of years build a convincing case that parents should, indeed, talk to their children. Talking in the presence of their children (but to others) does not confer the same vocabulary benefit.
In the most recent study (Weisleder & Fernald, 2013), experimenters tested 29 Spanish-learning infants at age 19 months. The children wore a small device that made an audio recording of all speech to which the child was exposed. The audio recordings were analyzed by software meant to differentiate speech directed toward the child versus speech audible to the child, but directed to others. A subset of recordings was coded by human observers to ensure the accuracy of the software.
Recordings of a full day’s speech were analyzed and the results showed a huge range in child-directed speech; caregivers in one family spoke over 12,000 words to the child whereas in another family that figure was just 670 words. The amount of child-directed speech as not significantly correlated (r = .17) with the amount of overheard speech.
At 24 months the productive vocabulary of the children was measured by asking the parents to judge words that they believed their child understood and words that their child used.
Of greatest interest, the amount of child-directed speech at 19 months was correlated (r = .57) with vocabulary at 24 months. The amount of overheard speech at 19 months was not (r = .25).
The sample size in this study is limited and there were some quirky features. (E.g., the software sorting “child-directed” vs. overherd speech is good, but not perfect.) But my confidence in the conclusion is bolstered by reports of the same finding from another lab, investigating speakers of other languages: English (Schneidman et al, 2013) and Yucatec (Schneidman & Goldin-Meadow, 2012).
Why must speech be directed to the child?
Weisleder & Fernald administered another task at 19 months meant to measure word processing efficiency. They speculated that the effect of child-directed speech on vocabulary was mediated through efficiency—something like, for example, the speed and accuracy with which the particular phonemes of the child’s language are processed.
This doesn’t fully explain the difference between child-directed and overheard speech. The obvious hypothesis is that other cues (e.g. eye gaze direction) prompt greater attention to speech that is child-directed, and that attention is necessary to build efficiency.
More details will have to await further research. For now, we can say with greater confidence “talk to your children” not just “talk in the presence of your children.”
Hart, B. M., & Risley, T. R. (1995). Meaningful differences in the everyday experience of young American children. Baltimore, MD: Brookes.
Huttenlocher, J., Waterfall, H., Vasilyeva, M., Vevea, J., & Hedges, L. V. (2010). Sources of variability in children’s language growth. Cognitive Psychology, 61, 343–365.
Shneidman, L. A., Arroyo, M. E., Levine, S., & Goldin-Meadow, S. (2013). What counts as effective input for word learning? Journal of Child Language, 40, 672–686.
Shneidman, L. A., & Goldin-Meadow, S. (2012). Language input and acquisition in a Mayan village: How important is directed speech? Developmental Science, 15, 659–673.
Weisleder, A. & Fernald, A. (2013). Talking to children matters: Early language experience strengthens processing and builds vocabulary. Psychological Science, DOI: 10.1177/0956797613488145
If the title of this blog struck you as brash, I came by it honestly: it's the title of a terrific new paper by three NYU researchers (Protzko, Aronson & Blair, 2013
). The authors sought to review all interventions meant to boost intelligence, and they cast a wide net, seeking any intervention for typically-developing children from birth to kindergarten age that used a standard IQ test as the outcome measure, and that was evaluated in a random control trial (RCT) experiment.A feature of the paper I especially like is that
none of the authors publish in the exact areas they review. Blair mostly studies self-regulation, and Aronson, gaps due to race, ethnicity or gender. (Protzko is a graduate student studying with Aronson.) So the paper is written by people with a lot of expertise, but who don't begin their review with a position they are trying to defend. They don't much care which way the data come out. So what did they find? The paper is well worth reading in its entirety--they review a lot in just 15 pages--but there are four marquee findings.
First, the authors conclude that infant formula supplemented with long chain polyunsaturated fatty acids boosts intelligence by about 3.5 points, compared to formula without. They conclude that the same boost is observed if pregnant mothers receive the supplement. There are not sufficient data to conclude that other supplements--riboflavin, thiamine, niacin, zinc, and B-complex vitamins--have much impact, although the authors suggest (with extreme caution) that B-complex vitamins may prove helpful.
Second, interactive reading with a child raises IQ by about 6 points. The interactive aspect is key; interventions that simply encouraged reading or provided books had little impact. Effective interventions provided information about how to read to children: asking open-ended questions, answering questions children posed, following children's interests, and so on.
Third, the authors report that sending a child to preschool raises his or her IQ by a little more than 4 points. Preschools that include a specific language development component raise IQ scores by more than 7 points. There were not enough studies to differentiate what made some preschools more effective than others.
Fourth, the authors report on interventions that they describe as "intensive," meaning they involved more than preschool alone. The researchers sought to significantly alter the child's environment to make it more educationally enriching. All of these studies involved low-SES children (following the well-established finding that low-SES kids have lower IQs than their better-off counterparts due to differences in opportunity. I review that literature here.)
Such interventions led to a 4 point IQ gain, and a 7 point gain if the intervention included a center-based component. The authors note the interventions have too many features to enable them to pinpoint the cause, but they suggest that the data are consistent with the hypothesis that the cognitive complexity of the environment may be critical. They were able to confidently conclude (to their and my surprise) that earlier interventions helped no more than those starting later.Those are the four interventions with the best track record. (Some others fared less well. Training working memory in young children "has yielded disappointing results."
) The data are mostly unsurprising, but I still find the article a valuable contribution. A reliable, easy-to-undertand review on an important topic. Even better,
this looks like the beginning of what the authors hope will be a longer-term effort they are calling the Database on Raising Intelligence--a compendium of RCTs based on interventions meant to boost IQ. That may not be everything we need to know about how to raise kids, but it's a darn important piece, and such a Database will be a welcome tool.
There is a lot of talk these days about STEM--science, technology, engineering, and math--and the teachers of STEM subjects. It would seem self-evident that these teachers, given their skill set, would be in demand in business and industry, and thus would be harder to keep in the classroom.A new study
(Ingersoll & May, 2012
) offers some surprising data on this issue.
Using the national Schools and Staffing Survey and the Teacher Follow-Up Survey, they found that science and math teachers have NOT left the field at rates higher than that of other teachers. In this data set (1988-2005) math teachers and science teachers left teaching at about the same rate as teachers in other subjects: about 6% each year.
Furthermore, when these teachers do leave a school, they are no more likely to take a non-education job than other teachers: about 8% of "leavers" took another job outside of education. Much more common reasons to leave the classroom were retirement (about 15%) or an education job other than teaching (about 17%).
The authors argue that teacher turnover, not teachers leaving the field, is the engine behind staffing problems for math and science classes.
So what prompts teacher turnover?
The authors argue that on this dimension math and science teachers differ. Both groups are, unsurprisingly, motivated by better working conditions and higher salaries, but the former matter more to math teachers, and science teachers care more about the latter.
But in both cases, the result is that math and science teachers tend to leave schools with large percentages of low-incomes kids in order to move to schools with wealthier kids.
Ingersoll, R. M., & May, H. (2012). The magnitude, destinations, and determinants of mathematics and science teacher turnover. Educational Evaluation and Policy Analysis, 34, 435-464.
The data are unequivocal: kids from wealthy families do better in school than kids from poor families. It's observable across ages, on all sorts of different measures, and (to varying degrees) in every country.A piece I wrote for the American Educator on this phenomenon is just out. You can read it here. A very brief summary follows.A great deal of research from the last ten years can be summarized in two broad theories. Family Investment theories offer the intuitive idea that wealthier parents has more resources to invest in their kids, and kids, naturally enough, benefit. Financial resources can go to enrichment experiences in the summer, more books in the home, a tutor if one is needed, better access to health care, and so one. Wealthier parents are also likely to be higher in human capital--that is, they know more stuff. Wealthier parents speak more often to their children, and with a richer vocabulary, with more complex syntax, and in a way that elicits ideas from the child. Wealthier parents are also more likely to read to their children and to buy toys that teach letters and the names of shapes and colors. Finally, wealthier parents are more likely to be rich in social capital--that is, they are socially connected to other people how have financial, human, or social capital. The second family of theories on this phenomenon is Stress theory.
Stress theories apply particularly to low-income families, and suggest that poverty leads to systemic stress--stress caused by crowding, by crime-ridden neighborhoods, by food uncertainty, and other factors. This stress, in turn, leads to emotional problems in parents, which leads to ineffective parenting strategies. Stress also leads directly to brain changes in children. Both of these factors lead to emotional and cognitive disadvantage for kids. The theory is summarized in the figure.
The article elaborates on these theories in more detail and I provide citations there.
I close with this paragraph:
The research literature on the impact of socio economic status on children's learning is sobering, and it's easy to see why an individual teacher might feel helpless in the face of these effects. Teachers should not be alone in confronting the impact of poverty on children's learning. One hopes that the advances in our understanding the terrible consequences of poverty for the mind and brain will spur policymakers to serious action. but still, teachers should not despair. All children can learn, whatever their backgrounds, and whatever challenges they face.