本研究根據社會困境理論所述的現象，假設團體成員在團體的集體作業中，懷有佔別人便宜的投機心態與擔憂被他人佔便宜的雙重心態，而推論流動性高的團體比起流動性低的團體會產生成員傾向出走的惡性循環。其中也伴隨有團體效能消極化及團體作業成果低落的情形。本研究包含三個子研究。研究一以48名大學生為研究樣本，三人為一小團體，採取實驗法將團體結構操弄為成員流動組與非流動組兩類，以合作投資遊戲，來分析團體流動性與團體成員出走傾向間的關聯；研究二以78名大學生為研究樣本，研究設計同於研究一，進一步分析團體流動性與團體效能間（以合作程度、信任程度為例）的關聯；研究三以台灣職棒球隊之球員流動性、年度排名、年度勝率為比較項目，瞭解團體流動性與團體表現間的關聯。綜合三個研究來看，團體流動性、團體動能與團體作業成果三者之間有著微妙的關聯。在開放型團體中，成員流動率偏高。在流動率高的團體裡，團員間的合作意願較低、彼此之間不容易信任、整體表現較差、出走意念較高、具體的出走行為也較多。然而，流動率應該並不是越低越好，適度的流動率反而有助於團體因應外界的威脅與變動，以維繫團體的整體表現。本文最後就團體成員流動的相關問題提出延伸討論。

Inspired by the Social Dilemma Theory (SDT; Dawes, 1980), the current project aimed to analyze the impact of free-rider behaviors and the fear of being taken advantage on collective tasks. The hypothesis envisaged was that higher membership turnover was related to poorer group performance, unstable group dynamics, and group destabilization phenomenon, respectively. The project comprised three studies. Study One recruited forty-eight undergraduate students for a lab-based experiment and estimated the influence of membership turnover on group destabilization, including: intention of leaving and actual leaving behaviour. Statistical results demonstrated that, compared to their counterparts, members from turnover-groups had a stronger intention of leaving groups and a higher occurrence of leaving behaviour. Study Two recruited seventy-eight undergraduate students and conducted a series of investment games in computer labs. The rationale was to compare group responses in terms of group trust and cooperation during the investment games. Statistical results indicated that, compared to their counterparts, members from nonturnover-groups were more likely to cooperate/trust with each other and had a better group performance. Study Three adopted six Taiwanese baseball teams as analytic samples. Statistical results revealed that both new-player-turnover (NPT) and exit-player-turnover (EPT) were negatively associated with the performance indexes. Specifically, higher-turnover teams (i.e., teams with higher NPT or EPT) were more likely to receive poorer performance indexes, such as inferior annual rankings and lower win odds. Cross-Analysis confirmed that high turnover is linked to group destabilization, but it remains undecided as to whether low turnover may contribute to group stabilization. In summary, the findings reported here have contributed concrete and useful information to the knowledge of group turnover and its impact on group stability and performance. The group leaders and organizational managers should be aware that all personnel manipulation and intervene programmes will not reach their optimal potential unless the impact of turnover has been appropriately tackled. Implication and limitation of the findings are discussed accordingly.