"The desire to avoid loss ran deep, and expressed itself most clearly when the gamble came with the possibility of both loss and gain. That is, when it was like most gambles in life. To get most people to flip a coin for a hundred bucks, you had to offer them far better than even odds. If they were going to lose $100 if the coin landed on heads, they would need to win $200 if it landed on tails. To get them to flip a coin for ten thousand bucks, you had to offer them even better odds than you offered them for flipping it for a hundred. "The greater sensitivity to negative rather than positive changes is not specific to monetary outcomes," wrote Amos and Danny. "It reflects a general property of the human organism as a pleasure machine. For most people, the happiness involved in receiving a desirable object is smaller than the unhappiness involved in losing the same object." It wasn't hard to imagine why this might be--a heightened sensitivity to pain was helpful to survival. "Happy species endowed with infinite appreciation of pleasures and low sensitivity to pain would probably not survive the evolutionary battle," they wrote."