When sadness and hope work to motivate charitable giving
研究发现，混合悲伤与希望的广告比单一情绪更能激发同情和灵感，从而增加对苦难事业的捐款；但认知负荷高时，混合情绪的效果会减弱。
Traditionally, charities that seek donations for human-suffering causes have relied heavily on emotional appeals designed to motivate negative feelings such as sadness and fear. Past research supports a sympathy-helping hypothesis that donation campaigns that use images of human-suffering to evoke sympathy and empathy increase prosocial behaviors. Empirical evidence also supports an inspiration-helping hypothesis whereby the positive emotion of strength inspires people to donate. Consistent with the proposed sympathy + inspiration-helping hypothesis, appeals that combine hope and sadness (vs. hope-dominant and sadness-dominant appeals) elicit sympathy and inspiration that motivate increased donations toward human-suffering causes. In addition, Study 2 results support that improving emotion appeals (sad to hopeful) generate higher donations than declining emotion appeals (hopeful to sad). Study 3 shows that cognitive load moderates the emotion-donation relationship. Under high load when mental resources are constrained, donations declined for the sadness + hope mixed emotion appeal.