Do people change in relationships or do they stop pretending?

Of course we change our behaviour according to who we are with. We don’t act in the same way toward a young child, an elderly relative, a stranger, a close friend, a shop assistant, an employer, a person who appears to be untrustworthy. We change according to the circumstances and how we perceive the other. But we still maintain our own integrity and personhood. Behaviour is what we choose, or should be according to circumstances.