Leadership signals approval of the new way of working and lets peers punish legacy behavior with small social penalties, so the pressure never looks organized and nobody senior owns it.
An example
After an auto parts supplier adopted a new production system, plant leadership hung posters with the new terms and praised teams who used them at the monthly town hall. No directive about the old terms was ever issued. Within weeks, line leads were correcting anyone who said work order in place of the new phrase, sometimes with a laugh, sometimes with an eye-roll. A quality engineer with twenty-five years at the plant kept using the old forms for a defect log the new system handled badly. The engineer stopped getting invited to the Friday coffee where the leads traded shift news, and a younger colleague started calling them the dinosaur in meetings. When the engineer complained to the plant manager, the answer was that people were just excited about the change.
Why it works
Complying becomes easy because it is the conformity path: adopters are spared the glances, the exclusion from informal channels, and the old-guard tag. Holding to legacy practice becomes costlier through a steady stream of small penalties, such as being left out of coffee or teased in meetings. Leadership never wields the stick, so it never owns the moral cost or the backlash, and it cannot easily switch the policing off once peers take it on. It works with a cohesive peer group, visible markers like terminology and rituals, leaders who keep their distance, and no counter-group large enough to make legacy practice a status marker.
The thinking behind it
Solomon E. Asch In Studies of Independence and Conformity: I. A Minority of One Against a Unanimous Majority (1956), Solomon Asch reported that about a third of responses on the critical trials went along with a unanimous wrong majority, though most responses stayed correct. Asch's Effects of Group Pressure upon the Modification and Distortion of Judgments (1951) found that one dissenting ally cut conformity sharply. Peer policing relies on the first effect; a senior figure who keeps a practice openly supplies the second.
Robert B. Cialdini Robert Cialdini's Influence (1984) describes social proof: the more people seem to be doing something, the more correct it looks. Once peers adopt the new vocabulary and tease those who do not, the new way looks like what everyone does, and leadership never has to issue a directive. It also explains the counter-group defense: a visible group that keeps the legacy practice supplies proof of its own.
Warning signs
Peers correct legacy terminology in meetings while leadership has issued no directive about it. Holdouts drop out of coffee conversations and informal channels. Teasing about old habits becomes routine and gets described as enthusiasm. Leaders praise adoption in public and answer complaints about the policing by saying it is not their doing. The pressure reaches behaviors leadership never meant to target.
How to defend yourself
Separate the substance from the social pressure. If a legacy practice is better for a specific task, show it with results, in writing, to the person who owns the process.
Find the senior figures whose standing does not depend on peer approval; when they keep a practice openly, the pressure loses force. Build a group large enough that the legacy practice becomes a status marker of its own, for example the engineers who own the defect data. Ask leadership directly whether the teasing reflects their wishes, because leaders who are asked to own the pressure often call it off.
How a leader shuts it down
If you want new habits, say what you require and own the requirement. Watch for teasing, exclusion, and labels aimed at holdouts, and stop them when you see them, because once peers take on the policing you lose control of what they police. Keep a route for people to argue a legacy practice on the merits.