>>11497043Learned, not programmed. We learned to appreciate fresh fruit eons ago, and we presumably learned to avoid rotten fruit shortly after. We rely on our sense of smell primarily to identify the traits we've instinctually internalized as signifying good or bad fruit. Sweets smell versus stanky smells. Vision is used too, but I don't know if the visual heuristics are instinctual, or learned during life.
