Introductions, lunches, and mentors in a new hire's first weeks all come from one faction, so the newcomer takes on its account of events and meets dissenters already labeled as bitter.
An example
Eight months after a reorganization had split its engineering leaders into two camps, a mid-sized payroll software company hired a vice president of product from outside. The chief technology officer's chief of staff built her onboarding schedule. Her first three weeks held twenty-two meetings, a welcome dinner, and a standing Thursday lunch, and every person on the list came from the chief technology officer's side. Several of them mentioned, unprompted, that the head of platform engineering was talented but had never gotten over the reorg. When she finally met him in week five, his objections to the roadmap sounded like the grievance she had been told to expect. She backed the roadmap at the quarterly planning review. Two senior engineers on his team resigned the following month.
Why it works
All four ways at once. Joining the faction looks better, because it comes with warmth, sponsorship, and the shortcuts a newcomer needs, and easier, because in the lonely first weeks it is the only social circle on offer. The dissenters' view looks worse, since it arrives pre-labeled as a grudge, and seeking them out later costs more, because by then it reads as disloyalty to the people who befriended you. It needs a new hire who is truly disoriented, a faction that controls calendars and introductions, and a coherent counter-view worth keeping out of sight.
The thinking behind it
Solomon E. Asch Effects of Group Pressure upon the Modification and Distortion of Judgments (1951) reports that when one other person in a group gave the correct answer, conformity to a unanimous wrong majority fell sharply. A newcomer who meets only one faction hears what sounds like a unanimous account. One early meeting with a dissenter plays the part of that partner, which is why the defense insists on it and why the faction labels dissenters before they are met.
Leon Festinger A Theory of Social Comparison Processes (1954) holds that people evaluate their opinions by comparing themselves with others, especially when no objective standard is available, and that they compare with people similar to themselves. A new hire has no standard yet for judging the company's disputes, so whoever is around in the first weeks sets the comparison. Controlling the first-month calendar controls whom the newcomer compares with.
Mark Granovetter The Strength of Weak Ties (1973) argues that acquaintances who bridge separate groups carry information that close circles do not. Onboarding run by one faction gives the newcomer strong ties inside that faction and no bridges to the other side. Cross-faction mentors and required introductions build exactly those bridges, which is why the leader's remedy is structural.
Warning signs
A new hire's first-month calendar contains nobody from the rival group. Warnings about particular colleagues arrive before the newcomer has met them, usually offhand and framed as friendly context. The official mentor, the onboarding buddy, and whoever books the welcome lunch all report to the same leader. Weeks later, the new hire repeats that group's account of a past reorganization almost word for word.
How to defend yourself
If you are the new hire, take back your own calendar early. Ask your manager or HR for a list of every peer and adjacent leader you will depend on, and book them yourself in the first month. When someone warns you about a colleague, meet that colleague soon and form your own view. Ask each person you meet who else you should talk to, and notice whose names never come up.
If you are the dissenter being pre-framed, reach the newcomer directly with something useful, such as how a process really works, before any history. A newcomer who arrives already knowing even one person outside the faction should use that link from the first week.
How a leader shuts it down
Assign mentors and onboarding buddies across factions, and have HR own the first-month calendar. Build a session with critics of current strategy into official onboarding, so newcomers hear the dissenting case from the people who hold it. Let senior hires set their own meeting list from day one. Whoever controls the new-hire stream shapes future votes and alliances, so give it a neutral owner.