For individuals that have either an acquired or naturally occurring reduced sensitivity to pain, the results can be fatal…. Clearly, feelings of pain (over just sensory-information) have an involvement in maintaining our evolutionary fitness. So what could this involvement be?
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[Psychology professor Shimon Edelman,] and his colleagues have proposed that, in addition to reinforcement learning, pain provides an independent, reliable basis for action-selection.Namely, pain is the paying of a cost that facilitates a reliable selection of courses of action in the face of adverse situations. Their theory invokes the conceptual framework of honest and costly signaling, which refers to a phenomenon that characterizes various types of signaling in nature. A classic example is the peacock’s tail: its great cost to its possessor guarantees the honesty of the message that it is intended to convey to the peahen (namely, that the peacock is a high-quality mate).
Pain, as it is experienced in our day to day lives, is often perceived as a problem, something to be suppressed and overcome. In truth, pain is usually part of the solution, a necessary evil that ensures we maintain our precious bodies, and behave in appropriate ways in an indifferent world.