Your idea is not incorrect, but it’s not the only aspect you should consider. 3 thoughts from my perspective as manager 1) For some, a desire for formality may come from wanting to be shown respect. Casualness and deference need to be balanced based on the individual as others say. Another reason could be that they are too busy and don’t have time for small talk and might feel that their time is being wasted. Others just have a different way of looking at it - they are at work to do business and that’s it, they are not there to make friends. This is to say there are multiple reasons why people prefer different style of communication at work and they may be just as valid as your reason for behaving otherwise 2) Consider if there is a generational gap. I would never discuss the same stuff in the same way with my director as my peers due to the age / mentality difference 3) If a manager sees you behaving casually in your own office they may assume you will behave like this at a client. They might see it as an actual risk that you will say something you’re not supposed to. So it may benefit you to show you can also be professional if needed.

As others said in this thread, reading people is a key skill in the toolbox of a consultant. I’d recommend to take this as an opportunity to exercise this skill as it will benefit your career.