such as...?
Before I retired, I tutored students who were having trouble at school, and worked as part of a team developing standard tests using written answers (instead of multiple choice). I observed that there was a distinct correlation between the scores and the use of cursive. Students who used cursive wrote longer answers, better thought-out answers, more correct answers; and the better the handwriting, the better the answers. I came to the inference that learning and practicing cursive developed fine motor skills, and that developing fine motor skills developed critical thinking skills. I didn’t get a chance to develop a study designed to test this hypothesis, however.