We examined the influence of prior expectations on 4- to 10-year-olds' and adults' preferences and emotions following an undesirable outcome (N = 205; 49% female, 51% male; 6% Asian, 1% Black, 13% Hispanic/Latino [non-White], 57% White, 18% multiracial, and 5% another race/ethnicity; 75% with a college-educated parent). Participants attempted to win a chance game with multiple prizes; the worst prize being a pencil. The game was rigged so that half of the participants lost, and the other half won. Regardless of the game outcome, everyone received a pencil. For winning participants (high-expectation condition), the pencil was worse than the prize they expected; whereas for losing participants (low-expectation condition), the pencil was better than the "nothing" they expected. Participants rated how much they liked and felt about the pencil preoutcome, postoutcome, when imagining having held an alternative prior expectation, and after learning that everyone received a pencil. Results showed that 6- to 10-year-olds and adults with low (vs. high) expectations liked the pencil more, with emotion ratings trending in the same direction. Prior expectations did not influence younger children's affective experiences. More participants with low (vs. high) expectations also expressed a positive outlook about the pencil, which increased with age and correlated with higher postoutcome emotions. More adults than children explained emotions as caused by thoughts, and only adults consistently reasoned that their preferences and emotions would have differed had they held alternative prior expectations. Once knowing that everyone received a pencil, 6- to 10-year-olds and adults liked the pencil more and felt better. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Four- to 10-year-olds and adults (N = 205) responded to vignettes involving three individuals with different expectations (high, low, and no) for a future event. Participants judged characters' pre-outcome emotions, as well as predicted and explained their feelings following three events (positive, attenuated, and negative). Although adults rated high-expectation characters more negatively than low-expectation characters after all outcomes, children shared this intuition starting at 6-7 years for negative outcomes, 8-10 years for attenuated, and never for positive. Comparison to baseline (no expectation) indicated that understanding the costs of high expectations emerges first and remains more robust across age than recognition that low expectations carry benefits. Explanation analyses further clarified this developing awareness about the relation between thoughts and emotions over time.

We examined developmental differences and sources of variability in trait reasoning. Four- to 10-year-olds and adults (N=198) rated how mean or nice "medium-mean" and "medium-nice" babies, kids, and teenagers were earlier in their lifetime and would be at older ages. Participants expected nice-labeled characters to be nice throughout their lives (participant age effects were null). In contrast, we documented age-related differences in judgments about meanness. With increasing participant age, individuals expected that meanness present in infancy, childhood, and adolescence would persist into adulthood. We discovered a curvilinear pattern in assessments of whether meanness originates during infancy: Four- to 5-year-olds and adults expected mean-labeled kids and teenagers to have been nicer as babies than did 6- to 10-year-olds. Controlling for age and working memory, participants with better inhibitory control more frequently expected mean-labeled individuals to remain mean across the lifespan, but inhibitory control was unrelated to judgments about nice-labeled individuals.