HANDEDNESS IN SWEDISH 10-YEAR-OLDS. SOME BACKGROUND AND ASSOCIATED FACTORS

Authors

  • Christopher Gillberg,

    Corresponding author
    1. Departments of Child and Youth Psychiatry and Pediatrics II, University of Göteborg
      Requests for reprints to: Dr. Christopher Gillberg, Barn-och Ungdomspsykiatriska Klin., Göteborgs Universitet, Box 7284, S-402 35 Göteborg, Sweden.
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  • Eva Waldenström,

    1. Departments of Child and Youth Psychiatry and Pediatrics II, University of Göteborg
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  • Peder Rasmussen

    1. Departments of Child and Youth Psychiatry and Pediatrics II, University of Göteborg
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Requests for reprints to: Dr. Christopher Gillberg, Barn-och Ungdomspsykiatriska Klin., Göteborgs Universitet, Box 7284, S-402 35 Göteborg, Sweden.

Abstract

Summary Forty-five left-handed and 46 right-handed 10-year-old children were subjected to a limited set of neurological tests and a square tracing task, ‘Pathological’ handedness was diagnosed in cases showing poor performance with the non-preferred hand on the squares task. The frequency of left-handedness in the population was estimated at 9.2%. The boy: girl ratio was 1.6:1. ‘Pathological’ handedness was twice as common among left-handers as among right-handers. Neurological dysfunction was more common in ‘pathological’ handers, especially left-handers. Reduced pre-, peri- and neonatal optimality was seen in boys with ‘pathological handedness’. School achievement problems and behaviour problems were much more common in left-handed boys than in other study groups. The results lend partial support for the extended pathological left-handedness model recently hypothesized by Bishop, but it is suggested that left-handedness in boys is more often a symptom of pathological shift of handedness than is left-handedness in girls.

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