As Thought Process

During the process of thinking, recognition occurs when some event, process, pattern, or object recurs. Thus in order for something to be recognized, it must be familiar. This recurrence allows the recognizer to more properly react, and has survival value.

When the recognizer has correctly responded, this is a measure of understanding. For example, when some animals have never seen a human being before, they do not hide and show no fear; but when they learn that a human being may be a threat, they may emit distress cries, flee or hide.

Even non-mammals can recognize when a situation signals danger, and will flee or hide. Baby spiders will flee when a mother spider sends a sharp pulse along the spider web. A male spider will gently poke a female spider's web to assess whether it is safe to approach the female without being killed himself.

As Social Process

When some person is recognized, they are accorded some special status, such as a name, title, or classification. Recognition can take many forms, such as mention in the mass media.

Acculturation

It becomes easier for persons to become accepted into some social process if they allow themselves to fit in, as a signal that they implicity accept some social norm. Thus the use of uniform dress is a signal for both group inclusion and acceptance. "Gangs" use signals and dress for this purpose.

Dress codes and norms even occur for religious groups.

As Technological Challenge

The technology for correct identification and classification for objects and even people has evolved over centuries. See, for example, pattern recognition.

Some History

For example, in the history of China, the Qianlong Emperor used large circular logos the size of a dinner plate to identify members of his family, and to distinguish them from his ordinary Han subjects, who had another symbol on their backs. This allowed his guards a method for easy recognition.

Current State of the Art

There is no foolproof technology or mechanism for recognition, currently. The best that can be done today is self-identification and self-classification, which works only when the principals are acting in good faith and are not deceivers.

Thus recognition also bears a measure of risk, that one is wrong.