Of the three categories, I believe this may be the most important. Every interaction we have at work has the potential to add something positive, take something away or, occasionally, be neutral.
Communication matters. Civility matters. Respect matters. Inclusion matters. Support matters.
And leadership matters enormously because the behaviour of a supervisor or manager often carries more weight than the same behaviour from a coworker. Social exclusion, poor communication, disrespect, unresolved conflict and lack of support can become significant psychological hazards.
It is also very difficult to solve other workplace problems when people cannot communicate with one another. If a team cannot have respectful disagreement, friendly conflict or an honest conversation, how are they going to solve problems involving workload, work processes or safety?