Writing it down by hand
Every few years somebody proposes that handwriting be dropped from the school timetable, and the argument is always sensible on its face. Almost no adult work is now done with a pen; typing is faster, more legible and easier to correct. If the purpose of teaching handwriting is to produce adults who write by hand, the subject has already failed.
But that is not the purpose, or at least not the only one, and the evidence that has accumulated points somewhere unexpected. Students who take notes by hand remember the content of a lecture better than students typing, and the gap appears specifically on questions about concepts rather than on questions about facts. The explanation offered is not that pens are magical. It is that typing is fast enough to transcribe and handwriting is not, so a person writing by hand must decide continuously what is worth recording, and that deciding is the learning.
This points to a different conclusion from the one usually drawn. If the benefit comes from being forced to compress, then the finding is about compression rather than about pens, and a typist who deliberately summarises should do just as well. Several studies have tested exactly this, and typists instructed to summarise do improve, although they tend to drift back to transcribing when the instruction is removed, which is a result about self-control rather than about writing.
There is a second and quite separate case for the pen, which concerns reading rather than memory. Learning to form letters by hand appears to help young children recognise those letters afterwards, and brain imaging shows different activity when a child has practised writing a shape rather than only looking at it. This argument applies to five-year-olds and says nothing about anybody older, which is worth noticing, because the two arguments are routinely presented together as though they supported the same policy.
The reasonable position is therefore less dramatic than either side would like. Teach handwriting early, because the reading evidence is specific and the children are not typing yet. Stop insisting on it in later years, where the evidence is really about summarising and can be obtained in other ways. And treat the question as empirical rather than as a matter of values, which is how it is almost always argued.