Final answer:
The student's inquiry pertains to social solidarity, which is characterized by a silent bond between individuals who share common interests or issues, demonstrating a tendency for social alignment and connection.
Step-by-step explanation:
The concept described in the question refers to a form of social solidarity, where individuals form a silent bond based on shared interests or common issues. This silent bond is often the result of any collection of at least two people who interact with some frequency and who share some sense of aligned identity.
The tendency for human beings to align themselves with groups with whom they share values and practices is a fundamental aspect of social interactions. In some cases, individuals may have shared interests but do not actively participate in formal groups or movements, highlighting the more personal, subtle connections between them. This is reflected in the anecdote where the two old people experience a silent companionship reflecting deep, unspoken understanding and shared experience.
These connections may be driven by shared cultural backgrounds, as seen in many couples, or together by the necessity to defeat common enemies, where individuals or groups set aside differences to collaborate towards a common goal, as in historical alliances or societal movements.