* Zero-sum theory is the idea that in some situations, if one person wins or gains something, another person has to lose an equal amount. Zero-sum thinking, also known as zero-sum bias or fixed-pie thinking, is when someone believes that if one person benefits, someone else must suffer. This way of thinking assumes that there is a limited amount of resources, so if one person gets more, another person must get less, fostering competition among participants. Our hypothesis: zero-sum bias means parasitic behavior while positive-sum bias means symbiotic behavior. We are researching: do humans see humans as a parasitic or a symbiotic species?