Q:

A japanese saying "一をいうと十返ってくる"

I'm currently trying to read a japanese novel and I found this expression : 

一をいうと十返ってくる

It was meant to qualify a character, but I just don't get it. At first I thought it could mean "tell one and give back ten", so I thought it meant this character tends to do more than he was actually asked or intended to do...?
However, I tried searching on japanese sites and it seems it's a saying to qualify a very proud person...? Still I would like to have a more precise idea of what it could really mean and where it does come from, because I'm very interested by japanese idioms.
Does anyone have a more precise idea ?
Thank you very much.

A:

「[一]{いち}をいうと[十返]{じゅうかえ}ってくる」

The meaning and nuance of this phrase can be quite different depending on the context or the speaker's intention.
Positive:
Someone is always willing to give a full explanation.  You ask one simple question and he will not only answer that question but also give you so much more related information.
Negative:
Someone always talks back to you.  Tell him one thing and he will give back a long session of objection, refutation, etc. 
(Possibly) more important:
I explained the phrase in terms of "speaking words" above, but the phrase does not always have to be about "ten times as many words".  It can also be about someone's tendency in taking non-verbal actions if he just is the type to do much more than the bare minimum.  

