This robust and subtle capability is hypothesized to be the result of eons of natural selection favoring people most able to quickly identify the mental State.

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This robust and subtle capability is hypothesized to be the result of eons of natural selection favoring people most able to quickly identify the mental state, for example, of threatening people, thus providing the individual an opportunity to flee or attack preemptively. In other words, processing this information subcortically (and therefore subconsciously) – before it is passed on to the rest of the brain for detailed processing – accelerates judgment and decision making when alacrity is paramount. This ability, though highly specialized for the processing and recognition of human emotions, also functions to determine the demeanor of wildlife.