Consciousness, Self-Awareness, Foresight, and Conscience:

Richard D. Alexander, Evolution and Humor, 1986:

"I see consciousness, self-awareness, foresight, and conscience as 'overrides' of more ancient and more immediate indicators of costs and benefits (such as pain and pleasure). Humans use consciousness, self-awareness, foresight, and  conscience to estimate long-term costs and benefits and to make decisions about rejecting short-term pleasures or accepting short-term pains. The special condition favoring such attributes, I hypothesize, is the ability of competing and cooperating humans to adjust continually the relationships between short and long-term costs and benefits so that intelligence, foresight, and deliberate planning have been the best available tools for realizing one's own interests."