There are two seemingly contradictory ideas of how company culture forms. In the first, culture is set from the top, cascading down from a vision, mission and values set by the company’s leadership. At its best, this can involve a group of people cohering around a clear and common goal, all pointing in the same direction. At its worst, this can be “management by motivational poster”, with unclear missions communicated badly by out-of-touch leaders to disengaged staff.

In the second, culture is something that bubbles up from the way that rank-and-file employees behave and interact. At its best, this can be dynamic and responsive, connected to how people in the business feel and reflective of the realities of their work. At its worst, this can be chaotic and confusing, impenetrable to outsiders, disconnected from any overarching and unifying mission, a group of “busy fools”.

These two views not actually contradictory, though. Culture is the sum total of how people in the organisation behave and how they interact with one another. These behaviours are influenced by countless factors, some of which are bottom-up and some of which are top-down. Company cultures are complex systems, in which cause and effect is impossible to untangle. It’s not just as simple as “people do as they’re told” or “people do as they like”.

Individual humans themselves are complicated and sophisticated. They have thoughts and feelings and desires, and sometimes they wake up in good moods and sometimes they wake up in bad moods. They like some of their co-workers and dislike others, and these relationships shift over time. They like some aspects of the work they do and dislike others, and this shifts over time too. They’re influenced by countless things inside and outside the organisations in which they work.

When you put these complicated and sophisticated humans into groups and ask them to work together, complicated and sophisticated behaviours emerge organically out of their interactions. These behaviours are, as Ralph Stacey puts it, “neither completely unpredictable nor completely predictable”.

Like all systems, cultures generally reach equilibria – stable states where they function at a certain level and in a certain way. That’s what culture is: the human system of an organisation, stabilised at a particular point and able to be characterised in some way. But these equilibria are fragile. Adding even just one new person to the team creates a whole new set of relationships and interactions and can profoundly change the culture, upsetting the system until it reaches a new equilibrium. That new equilibrium might be “better” or “worse” than the old equilibrium, but it will certainly differ in unpredictable ways from it.

An organisation’s leaders, then, can’t directly change their company’s culture in predictable ways. They might have a clear vision of what they’d like their culture to look and feel like, but it’s impossible to get directly there from whatever point they’re starting from. Attempts to say “this is our new culture” will generally produce unpredictable (and probably undesirable) results. That’s especially true if leaders try to incentivise cultural behaviours with targets and measurement: they will create perverse incentives and unforeseen consequences.

Leaders do have power. But it’s only the power to influence culture, to nudge it in the right direction. To wield that influence, it helps to understand and acknowledge that you have it – to recognise the power dynamic that exists in organisations. That means being a living example of the culture you’re trying to create; hypocrisy isn’t a great basis for positive influence.

Then, in order to influence the culture, you need to accept complexity – to “say yes to the mess”, as Frank J. Barrett puts it. You need to accept that your job is never done; culture is never complete, and it can evolve in both good and bad directions. You need to have a sense of what your end-state might look like, and a way of knowing whether you’re moving closer to it or further away from it. You need to embrace experiments, trying out small changes and then waiting for feedback, rather than undertaking wholesale culture re-engineering. And you have to be willing to accept that success might look different to what you first imagined.