Final answer:
In signed languages, it is not typical to switch between dominant and non-dominant hands as consistency in using the dominant hand is crucial for conveying accurate grammar and meaning. Handedness in humans is a form of brain lateralization and has implications for activities that require coordination, such as sports, where proficiency often differs between the hands.
Step-by-step explanation:
Switching between dominant and non-dominant hands when signing is generally not acceptable within signed languages, as handedness contributes to the grammar and meaning of the signs. However, there are some circumstances where switching hands may occur, for example, due to an injury. In general, sign language users maintain consistency with their dominant hand to avoid confusion.
Handedness is a form of brain lateralization that reflects the cognitive development in humans, and it indicates a reorganization of the brain over time. About 90% of humans are right-handed, a significant difference from apes, whose handedness distribution is closer to 50%. This development of handedness is connected with brain lateralization as seen in archaeological evidence from early human species like Homo habilis.
In other contexts, such as sports or physical abilities, it is more common to find individuals practicing to minimize the difference between their dominant and non-dominant hands. Studies involving activities like throwing or shot put show different levels of proficiency between the two hands, with dominant hands generally performing better. These differences can be evaluated through controlled hypothesis testing to assess the significance of the disparity between hand performances.