Reciprocity is considered one of the most potent weapons of social influence. Yet, little is known about when reciprocity appeals are more or less effective. A functional evolutionary approach suggests that reciprocity helps people survive in resource-scarce environments: When resources are limited, a person may not be able to obtain enough resources on their own, and reciprocal relationships can increase the odds of survival. If true, people concerned about resource scarcity may increasingly engage in reciprocal relationships and feel more compelled to reciprocate the favors done for them by others. In a series of experiments, I test this hypothesis and demonstrate that: (1) chronic concerns about resource scarcity (low socioeconomic status) predict increased reciprocity, (2) experimentally activating resource scarcity enhances the effectiveness of reciprocity appeals, (3) this effect is moderated by cues of persuasive intent, and (4) this relationship is mediated by increased gratitude.

Integrating research from life history theory with investigations of construal-level theory, the researcher proposes a novel relationship between life history strategy and construal-level. Slow life history strategies arise in safe, predictable environments where individuals give up current reproductive effort in favor of future reproductive effort. Correspondingly, high-level construals allow individuals to transcend the current context and act according to global concerns, such as the type of future planning necessary to enact slow life history strategies. Meanwhile, fast life history strategies arise in harsh, unpredictable environments where the future is uncertain and individuals need to pay close attention to the current context to survive. Correspondingly, low-level construals immerse individuals in the immediate situation, enabling them the flexibility needed to respond to local concerns. Given the correspondence between aspects of life history and construal-level, it seems possible that individuals adopting slow life history strategies should more frequently use high-level construals to assist in transcending the current situation to plan for the future, while individuals adopting fast life history strategies should more frequently use low-level construals to assist in monitoring the details of their harsh, unpredictable environment. To test the relationship between life history and construal, the researcher investigated whether or not a childhood cue of environmental harshness and unpredictability, childhood SES, and a current cue of environmental harshness and unpredictability, local mortality rate, influenced construal-level. In line with past research, the researcher predicted that childhood SES would interact with current cues of local mortality rate to influence construal-level. For individuals growing up in high SES households, a high local mortality rate will lead to an increase in high-level construals. For individuals growing up in low SES households, a high local mortality rate will lead to an increase in low-level construals. Overall, results did not support the hypotheses. Childhood SES did not interact with prime condition to influence either categorization or trend predictions. Examining how the prime interacted with another measure of life history strategy, the Mini-K, yielded mixed results. However, there are several ways in which the current study could be altered to reexamine the relationship between life history strategy and construal.