This is true of face to face conversation and to a lesser degree compuer-based communication. When we communicate electronically we have the ability to edit what we say before we send it but in face to face conversation - things we intend to conceal slip out in the heat of the moment.
But what I think really reveals us - even betrays us - is what we find funny - the jokes we tell and what we laugh at or even what we don't find humorous. Often a grin or a wry smile gives us away.
Our sense of humour is something we find hard to fake or suppress
There is nothing in which people more betray their character than in what they laugh at.
Credit: Johann Wolfgang von Goethe
Yet another reason why face to face conversation is so powerful.