Ambidextrous Children Have Greater Risk of Language, Behavior Problems
Is your child ambidextrous, or mixed-handed? According to a new study from Imperial College London and other European institutions, being ambidextrous—the ability to use both hands equally well—increases the risk of having language and behavior problems and difficulties with school performance.
Being naturally ambidextrous (versus teaching oneself to use both hands equally well) is very rare. Although experts are not certain what makes people mixed-handed, it is known that handedness is associated with the hemispheres in the brain. In people who are right-handed, for example, their left hemisphere is more dominant, and vice versa.
In the current study, the researchers evaluated 7,871 children from Northern Finland and identified 87 who were ambidextrous. The children were evaluated when they reached 7 to 8 years of age and again at 15 to 16 years of age. In the younger age group, parents and teachers assessed language abilities, school performance, and behavior. In the older group, the adolescents rated their school performance while their parents evaluated their children’s behavior.
The mixed-handed 7- and 8-year-old children were twice as likely as their right-handed peers to have problems with language and to do poorly in school. Among the 15- and 16-year-old mixed-handed adolescents, the researchers observed twice the risk of having symptoms of attention deficit hyperactivity disorder (ADHD). The ambidextrous adolescents also had more severe symptoms of ADHD than their right-handed counterparts and greater difficulties with language than either their left- or right-handed peers.
The results of this study do not suggest that all children who are ambidextrous have learning challenges. In fact, Dr. Alina Rodriguez, the study’s lead researcher from the School of Public Health at Imperial College London, noted that most of the ambidextrous children did not have learning or other difficulties. The findings may, however, help teachers and other healthcare providers identify children who are at risk of developing certain problems and thus allow them to implement different teaching activities or programs.
Previous research has suggested that being ambidextrous may be associated with some challenges. British psychiatrist Professor Tim Crow reported more than a decade ago that “people who are truly ambidextrous are slower to develop verbal and non-verbal skills.” Crow analyzed data from 12,770 one-year-old children taken in 1969 as part of the UK National Child Development Study. Over time, the children were evaluated for handedness and tested for verbal, reading, and math abilities. While both left-handed and right-handed children performed similarly, the ambidextrous children did dramatically worse in all three tests.
Dr. Rodriguez and other investigators think that differences in the brain may explain the learning, mental, and behavioral difficulties they reported in these ambidextrous children. More research is necessary to explain the differences and their impact on the brain. For now, today’s ambidextrous children should know they have some impressive company: Harry Houdini, Leonardo da Vinci, and Benjamin Franklin were reportedly mixed-handed as well.
Crow TJ et al. Neuropsychologia 1998 Dec; 36(12): 1275-82.
The Guardian, Jan. 26, 2010
Imperial College London, news release Jan. 25, 2010