One of the theories George H. Mead is known for later in sociology became the Theory of Symbolic Interactionism. Mead described that man was a social creature. That everything to man including sounds, gestures, words, and letters were symbols. Man used these symbols to operate in society. According to Mead objects are given meaning based on the socially constructed definition arising out of contact with objects.
Meaning exists totally within the social situation.
For Mead, meaning is given to symbols or gestures and this is key in the creation of the social creature. Significant symbols are different in that they have ascribed to them specific meaning in a social situation. For example, if an organism were to scratch their tooth repeatedly, only those involved within that social situation might be able to interpret that gesture and subsequently be able to respond. This is the essence of the significant symbol. It has meaning.