Very often, each individual continues to do something for his/her individual advantage that collectively is damaging to the group as a whole. The conflict is labeled as "social dilemma" or "social trap" by social psychologists. The phenomenon is very common in individualistic cultures (the West), but does the same phenomenon exist in collectivistic cultures which value cooperation and group goals more than individual benefits? The present authors employed a "replenishable ocean resource paradigm" that they developed on a series of studies in Taiwan and found that selfish behaviors were indeed very pervasive in the East. Several significant factors that affected the degree of cooperation and/or competition were also identified: sanction system, personal motivation, interpersonal relation, and the composition of decision making groups. In brief, it was found that the lower the severity of punishment or the less probability of being caught, the more selfish the subjects' behaviors became. Subjects with the motives to maximize "individual gain" and "relative gain" competed more and did not differ from each other, while "joint gain" subjects competed the least. In addition, decisions made by group of three or five people were more selfish than the decisions made by the individual. The present authors and their associates also compared the behaviors of Taiwan and American students in the social dilemma situation directly. It was found that subjects from two cultures did differ on the cooperative behaviors. Taiwan subjects were more competitive than American subjects in general. Both "probability of inspection" and "degree of punishment" had significant effect on the Taiwanese's behaviors , but only "inspection probability known or not" affected American subjects. In respects to Collectivism/Individualism Scale, Taiwan subjects did not score higher than American subjects on total collective measure, but Taiwan subjects scored higher than American subjects on collectivism toward spouses, parents, and relatives, and scored less than American subjects on collectivism toward colleagues/classmates and friends. Therefore, Taiwan subjects interacting with colleagues/classmates or friends were more selfish than American subjects. General discussion on the meaning, application and cross-cultural implication of this series of studies concludes this paper.