[Sabio]

Left handed people have left hemisphere dominance

• 95% of right-handed people have left-hemisphere dominance for language.
• >55% of the left-handed people have left-hemisphere dominance.
• 18.8% of left-handed people have right-hemisphere dominance for language function.
• 19.8% of the left-handed people have bilateral language functions.

References;
http://en.wikipedia.org/wiki/Lateralization_of_brain_function
http://www.ncbi.nlm.nih.gov/pubmed/20656040

http://en.wikipedia.org/wiki/Lateralization_of_brain_function#cite_note-psycho2-4