The belief in a decline in cooperation in the USA and China.

Amidst growing global challenges, perceptions of human cooperation-a cornerstone of societal progress-appear to be in decline. Despite empirical evidence showing that people in both the USA and China exhibit increased cooperation in experimental games, the public remains convinced that morality and trust-two key ingredients of cooperation-have declined over time. To investigate this paradox, this study examines trends in cooperation that people perceive from the past into the future, along with the reasons they perceive to underlie these trends. We conducted a cross-cultural survey of 628 Americans and 449 Chinese, asking them to estimate the likelihood of others' cooperative behavior in a prisoner's dilemma game and to rate four cooperation-related traits-warmth, morality, assertiveness, and competence-at various times between 1960 and 2030. Participants also provided reasons for their beliefs. Our findings revealed a stable belief in declining cooperative behavior in the game, along with all four traits, with a relatively small decline in competence, in both the USA and China. Moreover, over 60% of respondents believed in a more general decline in cooperation. Declining social trust and increasing stress and wealth were the primary perceived reasons for their beliefs in both countries; also, increasing exposure to social media was a stronger perceived reason for U.S. participants, whereas increasing education was stronger for Chinese participants. This study reveals a widespread belief in the declining cooperation in two of the world's largest nations and highlights the profound influence of sociocultural factors on public beliefs.