We, and our relationships are affected by:

● Our personalities

● Our preferred learning and thinking styles

● The group and people dynamics around us, and, of course:

● Everything else.

We don't have a model for that last one.  What we do have is psychometrics and some guesswork..

Psychometric tests attempt to define, measure and quantify personality.  All of them fail in some way - they are all incomplete and imperfect.  That is perhaps not surprising: if we were simple enough to be understood, we probably wouldn't be clever enough to understand ourselves.  However, we do understand some aspects of personality well enough for the models to be useful.  The most scientific model we have at the moment is that of the "Big Five" personality traits, as measured by the NEO Personality Inventory, also known as the NEO 5 Factor model.

However valuable it may be as a tool for academics and healthcare professionals , NEO tends to be of limited use in daily life.  The Myers-Briggs Type Inventory (MBTI) was developed before the 5-factor model but clearly reflects the same basic ideas and factors.  Whilst clearly "wrong", MBTI has the advantage of being useful, so long as you take note of the  limitations.  Another model that is practically useful is Michael Kirton's Adaptor-Innovator model, the "KAI" score, which reflects specific traits.

To the extent that we can measure personality, if we can understand our own, we can also understand other people, and how we differ from (or are similar to) them, using the same techniques.  The concepts of "Emotional Intelligence" and "Self Mastery" also relevant to understanding and managing oneself.  Having a model of your own personality is a good start for knowing what you have to manage.  Each of these offer models for understanding our differences and similarities, and how these affect us.

Our personality traits express themselves most clearly in how we work together (or not).   The is more about facilitation, which is more of a practical craft than a set of knowledge.  However, if we have a good model for personalities, then we're better able to facilitate groups that involve different types.  These areas are all related, but perhaps the best starting point is to know yourself.