Psychological effects of temporal landmarks: A meta-analysis of affective, cognitive, and self-regulatory processes.

Temporal landmarks, distinct time points that may shape affect, cognition, and self-regulatory behavior, have effects whose magnitude and boundaries remain uncertain. This meta-analysis systematically synthesized findings on the psychological outcomes linked to temporal landmarks in consumption and decision-making contexts. Following a comprehensive literature search and screening, 31 studies with 83 effect sizes (total N = 13,765) were included, encompassing experimental, quasi-experimental, and cross-sectional designs. The primary three-level random-effects model with study-clustered CR2 inference indicated a small positive average effect (g = 0.332, 95% CI [0.050, 0.614], p = 0.023). High heterogeneity (I2 = 90.8%) indicates that this pooled estimate is a context-dependent average tendency rather than a stable or broadly generalizable effect. Excluding nine studies with methodological concerns yielded a similar positive estimate (g = 0.395). Beginning and special-event temporal landmarks had positive subgroup averages, whereas the effect of ending temporal landmarks was uncertain. Longer time spans were stronger only in unadjusted analyses, and cultural moderation appeared only in a small subset of special-event effects; neither pattern was robust in multivariate meta-regression. These findings support a cautious psychological account centered on temporal cognition, self-representation, and goal regulation.