Neither side in a merger experiences itself as having a culture. Each experiences itself as behaving reasonably, and the other as behaving strangely.
This is not a figure of speech. It is the operative fact of post-merger integration, and almost everything that subsequently goes wrong can be traced back to a failure to take it seriously.
Culture is invisible from inside it
Ask an executive from either organisation to describe their company's culture and you will get a list of values, most of which are also on the other company's list. This tells you nothing, because culture is not what an organisation believes about itself. It is the set of assumptions so deeply held that nobody thinks to state them.
How much dissent is appropriate before a decision, and how much after. Whether a deadline is a commitment or an aspiration. Whether escalating a problem is responsible or a confession of inadequacy. Whether the person who speaks last in a meeting has more authority than the person who speaks first. What it means when the chief executive says "let me think about that."
None of this appears in an integration plan. All of it determines whether the integration works. And crucially, none of it is visible to the people who hold it — because to them it is not culture at all. It is simply what reasonable people do.
Culture is not what an organisation believes about itself. It is the set of assumptions so deeply held that nobody thinks to state them — and therefore nobody thinks to reconcile them.
The synergy case rests on a judgement that does not exist
Every merger is justified by a set of decisions that will be taken after completion. Which products survive. Which sites close. Which of two functioning operating models becomes the operating model. Who leads what.
These are the decisions that create or destroy the entire value of the transaction, and they will be taken by a group of executives who, at the moment they take them, have no basis whatsoever for trusting one another's reasoning. They have not seen each other under pressure. They do not know which of their new colleagues overstates and which understates. They cannot yet distinguish a genuine objection from a positioning move — and they are, all of them, aware that some of the people in the room will not be in the room in a year.
The synergy case, in other words, assumes a quality of shared executive judgement that does not exist and has not been built. It is generally assumed to be a matter of time. It is not. Left alone, it does not arrive; what arrives instead is a stable arrangement in which each side has learned to predict the other's behaviour without ever coming to trust it.
Why the integration plan does not touch this
Integration is typically run as a structural and systems exercise, because those are the parts that can be planned, resourced, tracked and reported. Systems, org design, legal entity, finance, property, technology. Each has an owner, a milestone and a colour.
The cultural work is acknowledged in the plan — nobody omits it — and it is delegated downward, resourced thinly, and scheduled late. It is treated, in effect, as an aftercare programme: something to be done once the real decisions have been taken, in order to help people come to terms with them.
This is precisely inverted. The cultural work is not aftercare. It is the precondition. By the time it is addressed, the decisions that mattered most — who leads, which model prevails, whose way of working is now the way — have already been taken by a group incapable of taking them well, and have already told every person in both organisations exactly what kind of company this has now become.
The eighteen-month test
There is a simple diagnostic, and it costs nothing.
Eighteen months after completion, listen to how the executive team speaks. Count the instances of the word they.
If the executives of the acquiring organisation still say "they" about the acquired one — or, more revealingly, if the acquired executives still say "they" about the parent — then whatever has been integrated, it is not the leadership. Two systems are still running. The synergies in the case will be reported as delivered, because they are reported by people whose credibility depends on their having been delivered, and the organisation will quietly know otherwise.
What actually works
The intervention that works is unglamorous and early: build a single functioning decision-making body out of two, before it is asked to take the decisions on which the transaction depends.
That means putting the assumptions on the table — not the values, the assumptions. How we escalate. How we disagree. What a commitment means here. What happens to the person who brings bad news. It means doing this explicitly, in a room, with someone present whose position does not depend on which side prevails.
And it means doing it in the first ninety days, when it is still possible to describe the differences as differences rather than as evidence — because after about a year, every difference has become a grievance with a history attached, and the work is three times as hard and half as likely to succeed.
Laszlo Cser is the founder of Vantaris Consulting, an executive leadership advisory practice working with organisations whose executive decisions carry significant commercial, operational or reputational consequence. More essays.