Rebecca Masterton, Dr Rebecca Masterton graduated with a BA in Japanese Language and Literature; an MA in Comparative East Asian and African Literature and a PhD in Islamic literature of West Africa. She has been... Answered 2 months ago

It is narrated that the Imams had shoulder-length hair (see the book Wahhabis' Fitna Exposed, which narrates a famous narration about Imam al-Ridha (as) when he was stopped on his way to Merv, and he pulled back the curtain on his howdah), but I am not aware of any particular fiqh that advises what is recommended.