Mead identifies two forms or levels of social interaction in human society. He refers to them respectively as “the conversation of gestures” and “the use of significant symbols”; I shall term them respectively “non-symbolic interaction” and “symbolic interaction”. Non-symbolic interaction takes place when one responds directly to the action of another without interpreting that action; symbolic interaction involves interpretation of the action.

[…]

In their association human beings engage plentifully in non-symbolic interaction as the respond immediately and unreflectively to each other’s bodily movements, expressions, and tones of voice, but their characteristic mode of interaction is on the symbolic level, as they seek to understand the meaning of each other’s action.

Harold Blumer, Symbolic Interactionism, pp. 8-9.