The deal closes, the press release goes out, and the synergy math holds up beautifully on paper. Then Tuesday arrives, and two workforces show up carrying entirely different sets of behaviors and expectations about how to get work done. McKinsey has found that 95% of executives call cultural fit critical to integration, yet 25% name its absence as the primary reason integrations fail. That gap between expectation delivery and behavioral reality is where most of the value post-merger is lost. Tamar S. Cohen, Workplace Strategist at HaloEffect, argues the failure is a cultural design failure, and leaders keep reaching for the wrong toolkit to fix it.
The Habits Nobody Renegotiated
What survives a merger intact, according to Cohen, are the team behaviors and habits. “How decisions get made, who gets copied on what, whether you speak up in the meeting or after it, how fast ‘urgent’ actually means: those habits were built over years of watching what got rewarded and what got punished,” she says. Employees learned those rules by observation, not instruction, and no announcement will immediately change them. The org chart changes, the branding changes, but the daily operating instincts stay exactly where they were.
Cohen watched this play out directly. In one merger she managed on the acquiring side, top performers from the acquired company began to struggle, not because they had lost their capability, but because the environment had changed the scoring system. “They were used to working autonomously and independently, as speed and momentum were rewarded. In our organization, we focused on collaboration and partnerships, and so the incoming employees saw their meetings multiplied, ownership blurred, and decisions slowed while everyone waited for input from another team.” The result was frustration on both sides and rounds of mutual blame. High performers struggled, managers were burning out managing to new expectations, and leadership pushed everyone to figure things out quickly, to meet the demands of investors and the market.
Culture Cosplay Versus a Designable Question
The standard response is a values statement, a town hall, maybe a workshop, and a poster campaign. Cohen has a name for this. “Culture cosplay,” she calls it, “where the language updates faster than the understanding and willingness to abide do.” Comms teams spend days working on the vocabulary of the new organization, but no one owns the work of changing behaviors. Leaders often conclude that people are “disengaged” when, in reality, expectations weren’t discussed and sometimes dismissed outright.
Reframing the problem changes what leaders can act on. “When you call this breakdown a behavior design problem, the question changes from ‘what do we want people to believe?’ to ‘what do we need people to do differently on Tuesday, and what in their environment is stopping them?'” Cohen says. “That’s a designable question.” This way, the specific friction points become visible and fixable: how conflict gets surfaced, how risk gets escalated, how credit gets assigned. It then forces an accountability shift. “A culture problem is owned by no one. A behavior design problem belongs to the leaders who control the systems that shape behavior.” If nobody’s compensation, approval chain, or manager routine changes, no amount of messaging will produce a different outcome post-merger.
Read the Operations, Not the Survey
Engagement surveys are the default instrument and, in Cohen’s read, close to useless in the first year post-close. “Those survey results are distorted anyway because people answer surveys carefully when they’re worried about their jobs,” she says. A scared workforce reports what it thinks is safe to report. Leaders then congratulate themselves on scores that are based on a moment in time, not predictive of future productivity. The honest data sits elsewhere, in operations, where the behavior is truly measurable: Cohen’s recommends looking across silos – Are former top performers failing, or leaving? “Watch decision velocity: are decisions that took a week now taking three, with more people in the room and less clarity on who owns the call?” Meeting load and cc lists tell the same story, because “duplication and defensive alignment are how two untrusting cultures protect themselves from each other.” Add to this the number of complaints logged, reports about customer experience, and the results overall, then train managers to hear the language tells: how long people keep saying “we used to” and “they do it this way.” These are leading indicators an engagement score cannot produce but are also highly actionable.
Cohen’s practical advice starts earlier than most integration plans do. Conduct a behavioral audit of both organizations covering how decisions get made, how conflict is managed, how risk becomes escalated, as practiced rather than as described in the deck. Then pick the three to five behaviors that matter most to the deal outcome and define them with specific examples, so employees know exactly what those behaviors look like in practice. Leaders model them. Recognition and rewards programs get updated to reinforce them.
Align each behavior to a measurable metric, which will reveal more over time than any engagement survey. Finally, invest in the manager layer, because managers “are the transmission mechanism between the integration plan and daily behavior, and in most mergers, they’re translating a strategy no one equipped them to explain.” A merger that skips that layer has essentially decided its integration will be improvised by people who were never briefed.
Follow Tamar S. Cohen on LinkedIn for more insights on merger integration, behavior design, and organizational change.
