Describing the environment of reading growth in a diverse sample: The Florida Twin Project on Reading, Behavior and EnvironmentSara A. Hart12, Chris Schatschneider12 & Jeanette Taylor2
1Florida Center for Reading Research 2Department of Psychology, Florida State University
Nature and Nurture of the Development of Reading Behavioral Genetics has started to
weigh in Petrill et al. (2010) , Logan et al. (in press)▪ genetics & shared environment= where start in
reading▪ genetics & shared environment = where grow▪ Genetics independent, shared environment
overlapping
Christopher et al. (2013), Christopher et al. (in press)▪ Genetics on intercept and slope▪ Some partial evidence for shared
environment (especially slope)▪ Genetics overlapping, shared environment
(when there) independent
Nature and Nurture of the Development of Reading
Nature and Nurture of the Development of Reading Hart et al., in press
h2 c2 e20
0.10.20.30.40.50.60.70.80.9
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interceptlinear slopequadratic slope
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Nature and Nurture of the Development of Reading What are these environmental
influences?
h2 c2 e20
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interceptlinear slopequadratic slope
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Possible sources
Family environment Family SES? (e.g., Sirin, 2005) CHAOS in the home? (e.g., Hart et al., 2007) Home Academic environment? (e.g., Griffin &
Morrison, 1997) School environment
School SES (e.g., Hart et al., in press) Teacher/classroom quality? (e.g., Taylor et al,
2010)
Florida Twin Project on Reading Sample
Ongoing cross-sequential study 5,184 MZ (N=1,734) and DZ (N=3,450) twins 50% free or reduced lunch
Procedure In-school state achievement testing 3 x year Parent and child questionnaire mailed home Highlighting the role of behavior and the environment on
reading
Participants 1186 pairs = 413 MZ, 773 DZ Mean age (1st grade) = 6.73 yrs, SD = .47 yrs Taylor et al., 2013
Present study DIBELS Oral
Reading Fluency Common measure
of reading ability in schools▪ Highly related to RC
Fall measurement, grades 1 through 4 (03/04 – 08/09)
Kim, Petscher et al., 2010
Measuring the Environment Family environment▪ Family SES▪ CHAOS in the home▪ Home Academic environment
School environment▪ School SES ▪ Teacher/classroom quality
Present study
Measuring the Environment Family environment▪ Family SES: Free and Reduced Lunch Status▪ CHAOS in the home▪ Home Academic environment
School environment▪ School SES ▪ Teacher/classroom quality
Present study
Measuring the Environment Family environment
▪ Family SES
▪ CHAOS in the home: Parent CHAOS questionnaire (2010)
▪ Home Academic environment School environment
▪ School SES ▪ Teacher/classroom quality
Present study
(Matheny et al., 1995)
Measuring the Environment Family environment
▪ Family SES▪ CHAOS in the home
▪ Home Literacy Environment :Parent questionnaire (2010)
School environment▪ School SES ▪ Teacher/classroom quality
Present study
(Griffin & Morrison, 1997)
Measuring the Environment Family environment
▪ Family SES▪ CHAOS in the home▪ Home Academic environment
School environment▪ School SES : Mean Free and Reduced Lunch
Status of all children in same school as twins (07/08)
▪ Teacher/classroom quality
Present study
Measuring the Environment Family environment
▪ Family SES▪ CHAOS in the home▪ Home Academic environment
School environment▪ School SES
▪ Teacher/classroom quality : ORF reading gain of classmates of twins in a school year (grade 1)
Present study
Initial descriptive results
Biometric Latent Growth Curve
Biometric Latent Growth Curve…with measured environments!
Purcell & Koenen, 2005
Results
h2 c2 e20
0.10.20.30.40.50.60.70.8
interceptlinear slope
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Biometric Latent Growth Curve Modeling
Results Family Environment
Intercept Slope0%1%2%3%4%5%6%7%8%9%
Family SESCHAOSHLE
*
*
Results School Environment
Intercept Slope0%
2%
4%
6%
8%
10%
12%
School SESTeacher Quality
*
Results Combined Home & School
Environment
Intercept Slope0
2
4
6
8
10
12
Teacher Qual-ityCHAOS
*
*
Results Combined Home & School
Environment
Intercept Slope0
2
4
6
8
10
12
Teacher Qual-ityHLE
*
*
In total
Family environment (CHOAS and HLE) were significant predictors of where kids started
School environment (teacher quality) was a significant predictor of where kids grew
Combination models suggested that HLE and teacher quality worked additively
SES (family or school) was not a significant predictor
Limitations
The timing of each measure is not perfect New funding is allowing us to follow the
twins longitudinally with questionnaires
Conclusions It is possible to identify environmental
pieces, just like specific genes Given the importance of shared
environment to growth of reading, knowing what the c2 is will allow us to better understand what influences reading development
The home environment has a role too! Especially it seems on where kids start in
grade 1
Conclusions
The effect of each measured environment is small? But greater or in line with what
molecular genetics is finding!▪ The phenotype is messy▪ No reason to believe not many environments
of small effect in typical population?
Acknowledgements
National Institute of Child Health and Human Development P50 HD052120.
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ECA
Results-Individual differences in growth
Results-Mean Growth Line
Intercept: 26.55
Linear Slope: 54.10 Quadratic Slope : -
9.39
x2(df) = 267.21 (4) p <.001CFI .95, TLI .87, AIC 73882.73, BIC 73981.59RMSEA .14, SRMR .03
