[quote=@Ariamis]
On that note, is it better to respond to everything you think your character would have a say in, even if it's a conversation between other people, or should one be more selective with what they respond to, to keep up realism? The first option would have a lot more content and interactivity between the characters, but I understand how it could get annoying if someone interrupts your dialogue with their own opinions or thoughts on the matter.
[/quote]

Never do the first option you gave. You should keep your character, [i]in character.[/i]

Anyway, if it's in your character to respond, then yeah? Like if he's a vocal person who hates liars and notices the conversation about a liar between two others, he SHOULD react. People usually don't mind if you join in on their conversation. However, this is totally different from attempting to join every conversation and so forcefully.