Wow, thank you all for your input!
There are several things that come to mind when I read about your experiences:
1. To answer
@InkyFingers : language and geography influences the writing style that is taught in schools, because we have different cultures. The American cursive handwriting is descended from spencerian, while the cursive we use in France and Belgium is closer to English roundhand. Few people here would recognize a capital I or G in BP...
2. Teaching children how to write is very different from learning a new writing system as an adult. Adults are more methodical and should have fully developed their fine motor skills, while kids need to be entertained and don't always have the fine motor skills required to have a mature penhold (we spend a lot of time working on that, even with teenagers). This difference also explains why your hand and brain are still separating cursive and spencerian: one was taught to you as handwriting when you were a child and the other was studied when you were grown up. Each style / tool sparks different connections in your brain.
@Erica McPhee : kids need to make sense of what they're learning and they don't enjoy just repeating letters and doing drills! We seldom practice letters on their own because of this, but it's also important to not focus on form and give attention to movement : so we would practice a basic stroke (begin with the loop), do a few lines of loops, differenciate between a small and a big loop, and when the child is comfortable with the movement, we show them how to transform their loops into letters and how to write words. With e and l, we can write "le" and "elle" in French... we're lucky.
You'd do the same with other basic strokes (the i, the oval, the inverted oval is useful to introduce the arch,...) and gradually introduce new letters and build bigger words.
3.
@TeresaS You're not the first calligrapher to see that their handwriting deteriorated after learning calligraphy. For one, you're probably writing too fast, maybe to compensate for the slow movements of calligraphy. Speed is one thing and rhythm is another: don't just slow down, think about what you're writing.
My theory is that the study of letterforms makes us so familiar with form and movement that we are actually able to write faster (our brain can process the movement faster than before), but we just go too fast and lose rhythm and jumble all our strokes together... That's just from my own experience.
4.
@InkyFingers can you write Italic as fast as your normal handwriting? Italic was promoted by calligraphers and typographers (adults) because it's neat and legible, but it's not as efficient as a cursive and children tend to distort the letters (they're too angular, children find it easier to write rounded curves).
5.
@Zivio thanks for sharing these resources, they're very interesting! However, as I said, this works well for adults, but I doubt that children adhere to such exercises. We do timed drills (they write as many loops as they can within one minute) and I use a metronome, but they don't love it.
Handwriting is a very complex thing, so there's a lot to unpack!
Thanks for your comments, they're helping me see clearer ;-)