When a multinational retailer sends an employee across the world, the assignment rarely fails because of spreadsheets or HR manuals—it fails because nobody invited the new hire to lunch. This simple truth emerges from a landmark study by the University of Portsmouth and Reutlingen University, which challenges how companies think about global mobility.
The research, published in the Journal of Global Mobility, reveals something organizations have spent decades overlooking: international assignments succeed or fail based on human relationships, not policies alone. Millions of employees move overseas each year to build global expertise and strengthen international operations, yet many assignments crumble—often at significant financial and reputational cost. The culprit is rarely logistics. It's the absence of trust between expats and their local colleagues.
Professor Liza Howe-Walsh of the University of Portsmouth, who led the study, puts it plainly: "International assignments are often treated as a logistical or administrative exercise. Our findings show they are fundamentally social." The research draws on 25 in-depth interviews conducted across a multinational retail company, capturing voices usually missing from expatriate research—not just the expats themselves, but local colleagues, local line managers, and international HR professionals. This 360-degree perspective revealed how collaboration, learning, and knowledge transfer flourish when relationships work, and how quickly assignments unravel when they don't.
What matters most? The study identifies local line managers as crucial. Supportive leadership, clear expectations, and a positive team climate repeatedly emerged as keys to building trust. But beyond formal structures, the research highlights factors organizations often dismiss: informal social contact, shared workplace language, and intercultural training for all staff—not just the person relocating. Professor Hazel Gruenewald of Reutlingen University notes that "simple actions can make a significant difference. Encouraging informal interaction, providing intercultural training and ensuring transparency about rewards and responsibilities can prevent misunderstandings before they arise."
The research also surfaces less-discussed obstacles: envy among local staff when expats arrive with different compensation packages, the importance of off-work interactions, and how informal communication quietly builds or erodes trust. These aren't problems that better onboarding documents solve. They require intentional leadership and organizational culture that welcomes outsiders.
As hybrid and remote work transform international assignments into something far more complex, these insights feel urgent. Dr. Roman Faller, co-author of the study, emphasizes the stakes: "Understanding the human relationships at the center of international assignments has never been more important." The study points toward a shift in how organizations should approach global mobility—moving beyond individual-focused solutions toward systemic changes that prioritize workplace environment, leadership behavior, and genuine integration.
For companies spending millions on overseas staff, the message is clear: policies matter far less than people. The difference between a thriving global assignment and a costly failure often comes down to whether someone made the newcomer feel genuinely welcome.