Erving Goffman developed the concept of "civil inattention" to describe the social practice of briefly acknowledging a stranger's presence in public and then deliberately withdrawing attention, framing it as a learned social rule.

Caveats

• Goffman's original framing emphasized civil inattention as an interactional 'ritual' and 'moral obligation' rather than explicitly calling it a 'learned social rule'—the latter is interpretive shorthand, not a direct quotation.
• The concept operates within Goffman's broader framework of 'unfocused interaction' and interaction order among strangers, which is broader than simple politeness—context the claim does not convey.
• Some supporting sources (e.g., Scribd uploads, unofficial web reposts) are low-reliability; the claim's accuracy is confirmed by higher-authority peer-reviewed sources.