The big idea
Mergers and acquisitions succeed or fail on people: culture, communication and keeping key talent decide whether the deal delivers.
In 60 seconds
- 2025 was a record year for M&A, yet acquirers often underperform, and people issues are usually why.
- Every stage of a deal has a people side: readiness and due diligence, combination, then integration.
- Culture takes years to integrate, but key talent can leave in months, so answer people’s “what about me?” questions first.
Do this: pick one live change you are leading and answer each person’s “me” questions in a one-on-one this month.
The workshop slides
Mergers & Acquisitions
The human capital side of M&A.
Michael Lane Morris, PhD · Fisher Professor of Innovative Learning
Defining human-centered leadership
Human-centered leadership is the process of inspiring and mobilizing people to co-creatively tackle tough challenges and do things that matter.
Every merger is a tough challenge. We’re all in the same boat, and people decide whether it works.
Fast facts: M&A
deals worldwide in 2025, a record
About one deal every 10 minutes
2025 was a record year for deals.
- $4.9Ttotal value, up 37% from 2024
- $2.6Tfrom just 617 megadeals of $1B+
- ~$99Tin deals worldwide since 1985
Why now? Interest-rate cuts, investor confidence and megadeals.
Sources: PitchBook 2025 Annual Global M&A Report (January 2026); IMAA Institute. Providers count deals differently, but all agree value rose sharply.
Global M&A activity, 1985–2026
Deal value is back near its record.
Text version of this diagram
- 1985: 2,676 deals, $347B
- 1990: 10,814 deals, $540B
- 1995: 20,278 deals, $1,039B
- 2000: 39,783 deals, $3,623B
- 2005: 36,025 deals, $2,794B
- 2010: 44,844 deals, $2,750B
- 2015: 48,052 deals, $4,779B
- 2020: 47,307 deals, $3,269B
- 2025: 39,494 deals, $4,037B
- 2021: 58,308 deals, $5,236B (peak value)
- 2025: 39,494 deals, $4,037B
- 2026 estimate: 40,668 deals, $4,729B
North American M&A, 1985–2026
Most deal value happens in North America.
Text version of this diagram
- 1990: North America was 53% of global deal value.
- 1995: North America was 68% of global deal value.
- 2000: North America was 60% of global deal value.
- 2005: North America was 52% of global deal value.
- 2010: North America was 42% of global deal value.
- 2015: North America was 55% of global deal value.
- 2020: North America was 67% of global deal value.
- 2025: North America was 79% of global deal value.
M&A troublesome dynamics and trends
Deals often fall short, and people are why.
10.9pts
Acquirers underperformed
Completed acquirers trailed non-acquirers in 2024 (WTW).
44%
Culture clash
of M&A leaders say poor cultural fit is a top reason integrations fail (McKinsey 2024).
~50%
Management styles
blame cultural fit or integrating management teams (Bain 2023).
74%
Key talent walks
of CFOs see moderate-to-high key-talent turnover in year one (RGP 2026).
65%
HR isn’t ready
of HR leaders feel less than fully prepared for their deals (WTW 2025).
Sources: WTW; McKinsey; Bain; RGP, The Human Value Gap in M&A (2026); WTW 2025 M&A Barometer.
Purpose and definitions
Language matters.
Why do it? Synergy.
- Accelerate growth
- Gain efficiencies
- Diversify financially
- Reach global markets
- Access technology and resources
- Share innovation
Merger: two or more organizations join under one owner and management structure, creating a new organization. Acquisition: one company takes control of another by purchase or stock exchange.
Mergers: three major types
Same buyer. Three kinds of deal.
Text version of this diagram
- Horizontal: two firms in the same industry, such as a soft drink company and a mineral water company.
- Vertical: firms at different stages of the same value chain, such as a soft drink company and an artificial sweetener maker.
- Conglomerate: firms in unrelated industries, such as a soft drink company and a snack food maker.
Popular M&A scenarios
What are you really buying?
- Purchasing assetsAcquiring the assets, not the liabilities.
- Purchasing stockAcquiring both the assets and the liabilities.
- Human capital due diligencePeople come with the deal: as assets to develop, or as liabilities to manage.
Three major M&A stages
Before, during and after the deal.
- Pre-combination. Why do it? Plan so the combined organization succeeds.
- Combination. The legal and financial side of the transaction.
- Solidification and advancement. Put the integration plans into action.
Stage 1: pre-combination checklist
Plan the people side before you sign.
- 1BeforePre-combination
- 2DuringCombination
- 3AfterSolidification
Make the case
- Search for and select a candidate
- Create the M&A team
- Assess both cultures
- Prove combined beats separate
- Due diligence: financial, facilities, people
- Develop integration plans
Set up for success
- Plan knowledge and learning transfer
- Set screening criteria
- Define the leadership structure
- Set a clear vision and strategy
- Specify the desired organization
- Write the integration action plan
Stage 2: combination
Build the structure. Lead the people.
- 1BeforePre-combination
- 2DuringCombination
- 3AfterSolidification
Build the structure
- Select an integration manager
- Design and launch teams
- Set the new structure and strategies
- Retain key employees
Lead the people
- Motivate employees
- Manage the change process
- Communicate with stakeholders
- Develop new HR policies
Stage 3: solidification and advancement
Day 1 is where it gets real.
- 1BeforePre-combination
- 2DuringCombination
- 3AfterSolidification
Day 1
Answer the 5 W’s
Who? How? What? Where? Why? Make it safe and secure.
Weeks 1–12
Integrate the work
Physical moves, structures, work design and procedures. Rapid change initiatives.
Months 3–12
Integrate the cultures
Solve problems together. Stay focused on the customer.
Always
Communicate, communicate, communicate
Then evaluate what to learn for the next integration.
People reasons for M&A failures
Most deals fail for human reasons.
- Unrealistic expectations
- Hasty strategy, poor planning
- No unifying message
- Talent lost or mismanaged
- Power and politics over productivity
- Culture clash, no integration plan
- Transition management fails
- Transition costs underestimated
- Distracted leaders
HR drivers of M&A success
HR shapes the deal at every stage.
- Organization readinessBefore the deal: are our people and processes ready?
- People due diligenceWho and what are we really buying?
- Integration planningA people plan for Day 1 and beyond.
- LeadershipVisible, aligned leaders on both sides.
- CultureWhat to keep, change and build.
- CommunicationEarly, honest, often.
- Talent and retentionKeep the people who make it work.
- Rewards and benefitsFair, clear and harmonized.
Strategic M&A interventions
Eight ways to make the pieces fit.
- Culture alignment strategies
- Effective communication strategies
- Leadership and employee orientation plans
- Stress management strategies
- Support systems
- Change management tools
- Transition teams
- Knowing the relevant M&A law
M&A readiness matters
Most HR teams are not ready.
Text version of this diagram
- 65% of HR leaders feel less than fully prepared for their deal portfolio (WTW 2025).
- Fewer than 1 in 5 say HR was properly included in early negotiations (WTW 2025).
- 75% name talent retention as the most important integration success factor (WTW 2023).
- 58% say communication and change management are pivotal (WTW 2023).
- 54% plan to add change-leadership training; 50% now measure employee engagement through the deal (WTW 2023).
Culture strategies
Two cultures meet. They don’t mix on their own.
It takes leadership to bring them together.
Culture and distance
Close the cultural distance.
Our culture
How we do things here
←Cultural distance→
- Empathy
- Respect
- Adaptability
- Resiliency
Human-centered mindsets build the bridge.
Their culture
How they do things there
Cultural distance is how different two people or groups are. Every person has a culture of their own.
It’s an adaptive challenge. Closing it means changing people’s assumptions, beliefs, habits and allegiances.
Cultural distance hotspots
Where cultures collide.
| Dimension | Ways of… |
|---|---|
| Worldview | Perceiving the world: the lens for seeing it |
| Cognitive processes | Knowing and thinking |
| Linguistic forms | Expressing ideas and making meaning |
| Behavioral patterns | Acting and doing |
| Social structures | Interacting with yourself and others |
| Media influence | Channeling the message |
| Motivational resources | Deciding and valuing: moral reasoning and power |
Adapted from David J. Hesselgrave’s seven dimensions of cross-cultural communication (1991). Geert Hofstede’s dimensions of national culture are a useful companion lens.
M&A culture issues
Four ways cultures combine.
Text version of this diagram
- Integration: keep the best of both cultures.
- Assimilation: one side gives up its culture and adopts the other’s.
- Separation: each side holds on to its own culture with little exchange, which can breed resistance and clashes.
- Deculturation: people lose their old culture and don’t value the new one either.
Culture and talent take time
Culture takes years. Talent walks in months.
Deal closes
Day 1
Everyone starts asking what it means for them.
Year 1
74%
of CFOs see moderate-to-high loss of leaders or critical talent (RGP 2026).
Year 1
30%+
of the acquired firm’s executives leave, then about 21% a year for a decade (Krug and Shill 2008).
Years 5–7
Culture
is finally integrated, by HR chiefs’ estimate (RGP 2026).
Sources: RGP, The Human Value Gap in M&A (2026); Krug and Shill, “The Big Exit,” Journal of Business Strategy (2008).
Most critical people issues
You’re buying people. Plan to keep them.
Talent is the value
75%
of acquirers say keeping talent is the #1 factor in a successful integration.
Talent walks out the door
73%
struggle to keep key tech talent after a deal.
Smart buyers plan early
78%
now make key below-executive talent a top due-diligence priority.
Communication counts
58%
say communication and change management are pivotal.
Sources: WTW 2023 M&A Barometer; WTW 2025 M&A Barometer.
Most challenging people issues
Aligning cultures is the hardest part.
75%
of acquirers hit culture problems that need serious intervention.
Bain 2023
Is aligning cultures the #1 challenge of the whole deal?
44% of leaders say poor cultural fit is a top reason integrations fail (McKinsey 2024).
Runner-up: 66% struggle with data quality in due diligence (WTW 2025).
Sources: WTW 2025 M&A Barometer; Bain 2023; McKinsey 2024.
Employee key “me” issues
Everyone’s first question: what about me?
Before anyone hears the strategy, they are asking
“What about me?”
My job?
My title · My position · My responsibilities · My office space
My boss?
My decision-making authority · My procedures
My pay?
My bonus · My benefits
My future?
My security · My location
Meanwhile, on the farm
Answer the “me” questions first.
Text version of this diagram
- Panel 1: the Highland cow boss points at a picture of two barns: big news, we’re merging with Hilltop Farm!
- Panel 2: the KuneKune pig, the Sebastopol goose and the Nubian goat huddle, thinking: my stall? My boss? My job?
- Panel 3: the cow sits down at a table with them: let’s talk about what this means for you.
Challenges: morale and direction
Morale drops after a deal, most at the acquired firm.
The buyer’s people
Satisfaction dips after the deal.
The acquired firm’s people
The drop is 15% bigger.
What drops most
- Culture
- Management
- Trust
From 361 mergers matched to Glassdoor reviews, 2008–2020. Overall satisfaction falls about 6% of a standard deviation.
Source: Cai, Prat and Yu, “Mergers and Non-contractible Benefits: The Employees’ Perspective” (SSRN, 2026). WTW (2024) also finds people leave over a new direction they don’t buy into and a changing culture.
Leadership
Lead visibly through the change.
In a merger, people watch what leaders do more than what they say.
Join in
Role-model active participation.
Be seen
Manage by walking around.
Talk often
Casual, learning conversations.
Be straight
Punctual, transparent, authentic and objective.
Grow people
Stay development-oriented.
Keep promises
And deadlines.
Successful M&A human-centered leadership
What great M&A leaders do.
Culturally sensitive
Respects how both sides work.
Open-minded
Hears ideas from both companies.
Flexible
Adapts as the plan changes.
Self-aware
Knows their strengths and weaknesses.
Talent keeper
Committed to keeping key people.
Good listener
Listens before deciding.
Visionary
Paints a clear picture of the future.
Focused
Filters out distractions to focus on what drives success.
Transition and integration teams
Help people cross the neutral zone.
Ending
Letting go of the old company and old ways.
Neutral zone
“The nowhere between two somewheres.” Anxiety is high, and so is creativity.
New beginning
People commit to the combined company.
How a transition team gets people to the other side
Both sides at the tableVisible representation from each organization.
Welcome everyoneMeetings, orientations and introductions.
Who’s whoDirectories so people can find each other.
Show progressRegular reports on what is changing.
Honor the pastSensitivity to stress and to past contributions.
Transition model: William Bridges, Managing Transitions.
Change management tools
Tools to listen, reward and protect.
Listen
Hear concerns early, before people walk.
- Focus groups
- Exit interviews
- Performance appraisals
Reward
Recognize effort while things are hard.
- Bonuses and spot cash awards
- Flexibility benefits
Protect
Keep what you bought, and keep it fair.
- Non-compete and IP agreements
- Dispute resolution procedures
Effective communication strategies
Communicate early, often and deeply.
Each layer goes a little deeper than the one before.
Surface↓ Deeper
Multiple routes. One-on-one, groups, newsletters, intranet.
Thematic focus. Regular updates on progress. Metrics are key.
Awareness building. Explain why the deal happened.
Change reassurance. Road bumps are normal, and you’ll solve them together.
Deep level. Go beyond history and values to build community.
Key talent retention
Keep the people you bought.
The value of a deal walks out the door every night. Here are 25 ways to make sure it comes back.
25
retention strategies in three groups
Pay and performance8 strategies
Benefits and flexibility10 strategies
Protect and listen7 strategies
M&A retention strategies
Retention deals are everywhere, and mostly time-based.
72%
set aside retention pools
Companies that track or fund fixed retention payments.
75–100%
of base salary
The median retention award for the C-suite. 50% for other senior leaders, 30% for salaried staff.
73%
are time-based only
Most salaried retention deals simply pay people to stay (55% for senior leaders).
57%
say career moves work best
Better career opportunities and promotions are the most effective non-cash tactic for senior leaders.
So what? Money buys time, not loyalty. People still leave over culture, a new direction or a new manager.
Source: WTW 2024 M&A Retention Study.
Key talent retention strategies (1)
Pay, performance and onboarding.
Pay
Money that rewards staying and performing.
- Retention bonuses and contracts
- Sign-on bonuses
- Spot cash awards
- Relocation payback agreements
Performance
Clear expectations and a fair way through conflict.
- Timely performance appraisals
- Effective dispute resolution procedures
Onboarding
Help new colleagues belong fast.
- New hire orientation
- Rotational assignments
Key talent retention strategies (2)
Benefits and flexibility.
Time
Give people control over when they work.
- Flexible scheduling
- Job sharing
- Sabbaticals
- Shorter benefit waiting periods
Place
Give people a say in where and how.
- Virtual office and remote work
- Relaxed dress code
Life and growth
Support the whole person, and their next step.
- Tuition reimbursement
- Subsidized child care
- Employee services
- New programs
Key talent retention strategies (3)
Protect, listen and pay fairly.
Protect
Keep what you bought.
- Cease and desist letters
- Non-compete and IP agreements
Listen
Learn what people need, and why they leave.
- Focus groups
- Exit interviews
Pay fairly
Close gaps between the two pay systems.
- Accelerated salary increases
- Salary structure adjustments
- Lump-sum payouts
M&A resources
Go deeper.
Read
- The Complete Guide to Mergers and AcquisitionsTimothy Galpin and Mark Herndon
Step-by-step tools for every stage, from due diligence to integration.
- Managing TransitionsWilliam Bridges
The neutral zone and how to lead people through it.
- Winning at Mergers and AcquisitionsMark Clemente and David Greenspan
Plan the integration around customers and markets.
- HR Issues and Activities in Mergers and AcquisitionsRandall Schuler and Susan Jackson
The classic map of HR’s role in each stage.
Track the numbers
IMAA Institute
Deal counts and values worldwide since 1985.WTW M&A Barometer
How deals perform, and the people issues behind them.WTW M&A Retention Study
What companies pay, and do, to keep talent.
More research behind these slides
- McKinsey, “The culture compass” (2024): using early culture insights to plan integration.
- Bain, “Cultural integration” (2023): why culture work needs serious intervention.
- RGP, The Human Value Gap in M&A (2026): talent loss and the 5–7 year culture timeline.
- Cai, Prat and Yu (2026): employee satisfaction after 361 mergers.
- Krug and Shill, “The Big Exit,” Journal of Business Strategy (2008): executive turnover after acquisitions.
- Nahavandi and Malekzadeh, “Acculturation in Mergers and Acquisitions,” Academy of Management Review (1988): four ways cultures combine.
- PitchBook 2025 Annual Global M&A Report: the record year in numbers.
Try it: Merger People Check
Self-check · M&A human capital
Merger People Check
Think about a merger, acquisition or big reorganization you are leading or living through. Rate how often each statement is true. See your strongest and weakest area, and one move to make this month.
- 1Rate
- 2See
- 3Practice
Readinessdid we plan the people side before the deal?
HR was involved before the deal was signed.
We assessed both cultures, not just the finances.
Communicationdo people know what is happening and why?
People hear the why behind the deal, not just the what.
We update people regularly, even when there is no news.
The “me” questionsdo people know what it means for them?
Each person knows what happens to their job, boss and pay.
Leaders talk one-on-one with people about their future.
Cultureare we bringing two cultures together on purpose?
We name what to keep from each culture.
People from both sides work on real problems together.
Key talentare we keeping the people we need?
We know who our critical people are, by name.
Leaders reach out personally to the people we most want to keep.
Your people integration
Your result builds as you rate.
This is a reflection exercise, not a validated assessment. Your answers stay in this browser tab. Nothing is sent or saved.
Go deeper
Back to all Executive Education topics
Part of Executive Education from the Human Centered Lab: workshops Jules Morris, PhD and Lane Morris, PhD lead for working professionals. Slides adapted from Michael Lane Morris, PhD.
Frequently asked questions
Why do most mergers and acquisitions fail?
Most deals that fall short do so for people reasons: culture clashes, poor communication, distracted leaders and the loss of key talent. In McKinsey’s 2024 research, 44% of M&A leaders named poor cultural fit as a top reason integrations fail.
What are the three types of mergers?
Horizontal mergers join firms in the same industry, vertical mergers join firms at different stages of the same value chain, and conglomerate mergers join firms in unrelated industries.
What are the four acculturation modes in a merger?
Nahavandi and Malekzadeh (1988) describe integration, assimilation, separation and deculturation, depending on how much each side wants to keep its own culture and how attractive it finds the other.
How can leaders keep key talent after an acquisition?
Identify critical people early, reach out to them personally, answer their questions about their job, boss, pay and future, and use retention agreements. WTW’s 2024 study found 72% of companies fund retention pools.