so..

 " one in five" 

And i know none of the not -extant 'mental health professionals' will patiently tell their 'patients'..

" no there is no 'night person' archetype...  get a few months of porridge and tell them at check in ' sorry i am a night person so i can't get up at 7 for my porridge'... and they will give you a look...  a bit Alexei Sayle...  as if to say ' yer gotta be kiddin kiddo..' ... with a hungry missile ready to backup their assertion upon actual evolution.... " 

and thus assist the wonky one in five  to be not...