Gender differences in language are small but matter for disorders.

Gender differences in language can be signs of cognitive differences, but can also by themselves be the cause for such differences. Females have a slight linguistic advantage over males, but effect sizes are small, and gender explains very little of the variance seen in the normal population (1%-2%). However, males outnumber females in the lowest 10th percentile in language tests (2:1), causing males to more often be diagnosed with developmental disorders, which rely on tests of language development. Thus, gender differences in language are negligible, if you focus on the whole population, but if you focus on language deficits, gender differences are outspoken. Differences in voice and word use can be observed among the genders, making it possible to predict gender from these measures with a high degree of certainty. A subtle finding is that women use more first person pronouns. This is also observed in depression, which is more prevalent in females, opening up a potential link. Sex chromosome trisomies are often accompanied by language deficits, but the causes for this are not known. No gender differences are observed in the linguistic symptoms of neurodegenerative disorders. Poststroke aphasia is more prevalent among women than among men, but this seems to be an age-effect. A link between the brain and gender differences in language is thus missing.