View
217
Download
3
Category
Tags:
Preview:
Citation preview
Genes MatterSo What
Brian Byrne, Katrina Grasby and William CoventryUniversity of New England
Some personal reflections A single learning theory
Initial hypothesis: Letters represent morphemes
The phonetic module is buried in the cognitive unconscious
Learning print-speech pairs that reveal letter-phoneme relations ≠ discovery of alphabetic principle
Therefore, design and delivery of instruction is the main source of variance
WRONG!!!
Colorado Learning Disabilities Research Center and Institute for Behavioral Genetics
Twin designs
Identical (MZ) twins:100% genes in common
Fraternal (DZ) twins:Average 50% genes in common
Classic twin designWhen twins are reared within a family (that is, not separated at birth), variance can be partitioned thus:
genetic variance environmental variance
shared environment unique environment
total variance
Genetic, shared environment and unique environment influences on a trait can be estimated from the degree of similarity between twins as a function of zygosity
A = 2(rMZ – rDZ)
C = rMZ – A
E = 1 - rMZ
Reading (from International Twin Study of Literacy)
Kindergarten (words)
Grade 2 (words)
Grade 1 (words)
Grade 2 (text)
Extremes analysisHeritability of low- and high-ability reading
Grade Ability -1 SD -1.5 SD1 Low .58 .35*
High .69 .812 Low .63 .40*
High .76 .67
* N = 90, small for twin model, wide confidence intervals
All in all……genes really matter when it comes to
understanding sources of differences among school students in literacy (and numeracy) in Australian schools
This includes low-end scores, though evidence for more environmental influence at very low ability levels
An important observation
Kvaale, Haslam, Gottdeiner, Clinical Psychology Review, 2013
“We found that biogenetic explanations reduce blame…but induce pessimism (about recovery)…
Promoting biogenetic explanations to alleviate blame may induce pessimism and set the stage for self-fulfilling prophecies that could hamper recovery from psychological problems.”
A menu for ImplicationsIndividuals hampered by literacy difficulties
Practitioners and teachers
Researchers
Policy-makers
Politicians
Implications:For teachers and teacher training
Differences among teachers are not nearly as substantial as public opinion holds and the press promotes.
Basing teacher rewards on student achievement is unsound and could have unfortunate consequences (such as teachers’ reluctance to work in schools with poor NAPLAN results).
Nevertheless, because academic achievement is about means as well as variances, teaching and teacher training need to be as evidence-based as possible (e.g., the phonics/whole language issue).
Implications:For the educational system as a whole
The practice of comparing “like” schools on the basis of NAPLAN results is invidious because the comparator (ICSEA) is a distant proxy for student characteristics, including genetic endowment
Implications:For the educational system as a whole
Any additional funding flowing from NAPLAN testing should be directed towards individual students, not to schools for school-level changes (e.g., smaller class sizes, more computers….)
Implications:For the educational system as a whole
As the curriculum moves to be “national,” that is more uniform across the country, genetic influence will increase as environmental variance in the form of curriculum differences decreases.
Introduction to PsycholinguisticsBrian Byrne
University of New EnglandThank you to
Sally Larsen, Dipti McGowan
The families of the twins and the twins themselves
The Australian Research Council
The Australian Twin Registry
Recommended