1. Initial Situation

• Initially, there is a clear norm or tacit rule in the group:
  "We behave correctly, cooperatively, and respectfully."

• A few begin to exhibit deviant behavior – not out of necessity, but because they can and there are no immediate consequences.

2. Psychological Mechanisms

1. Model Learning (Bandura Effect)
   People strongly orient themselves towards the behavior of others, especially when they get away with it.
   → "If they're allowed to do it, I can too."

2. Lowering the Inhibition Threshold
   The first violation of the rule is internally difficult for many. If others have already committed it, the inner resistance disappears.
   → moral "permission" through observation.

3. Loss of Social Sanction
   If no one intervenes, the norm is considered "no longer binding." perceived.
   → Collective feedback: Silence = tacit consent.

4. Feeling of justice through leveling the playing field
   Some people break rules not to have fun, but to avoid being "the stupid one" who is the only one still following the rules.
   → "Why should I restrict myself when others benefit?"

5. Spiraling effect
   Deviant behavior spreads until it becomes the new norm.
   → Norm reversal: What was previously "wrong" was, is normalized.

3. Effect on the Collective

• Erosion of Trust
  The common foundation on which cooperation is based breaks down. Everyone expects others to act selfishly.

• Polarization
  Two camps emerge: those who continue to act correctly and those who exploit everything. This promotes mistrust and hostility.

• Self-Reinforcement
  The more people participate, the greater the group pressure for the remaining members – until resistance becomes almost impossible.

• Long-term consequences
  The original sense of community can be permanently damaged. Even if one tries to restore the old order, the memory remains: “It works if everyone only thinks of themselves.”

💡 Core psychology:
A few who break rules “just because they can” act like a weak point in the collective's immune system. If this is not corrected immediately, the “social virus” spreads – not because of malice, but because adaptation, imitation, and self-protection are deeply rooted in human nature.

If you like, I can present this to you in a chronology of collective norm erosion, showing step by step how it develops from isolated cases to a mass movement.
That would be almost like a psychological roadmap for social disintegration.

The phenomenon you are referring to has a clear parallel to social contagion and norm erosion – and it can trigger a chain reaction that deeply affects the psychology of the collective.