Assessing the Psychological Burden of Birth Order: A Comparative Study of Perceived Stress and Maladaptive Perfectionism amongst High School Siblings

Birth order may shape the roles, expectations, and responsibilities experienced by adolescents within their families, potentially influencing psychological outcomes such as perceived stress and maladaptive perfectionism. The present study examined differences in perceived stress and maladaptive perfectionism across elder, middle, and younger siblings and further explored the relationship between these variables among elder daughters. The sample comprised 104 high school students, and data were collected through an online questionnaire using the Perceived Stress Scale-10 (PSS-10; Cohen et al., 1983) to assess perceived stress and the Almost Perfect Scale-Revised (APS-R; Slaney et al., 1996, 2001) to assess perfectionistic tendencies. The Discrepancy dimension of the APS-R was considered an indicator of maladaptive perfectionism, reflecting the perceived gap between personal standards and actual performance. A one-way analysis of variance (ANOVA) was conducted to examine differences in perceived stress and maladaptive perfectionism across elder, middle, and younger sibling groups. Independent-samples t-tests were conducted to examine gender differences in perceived stress and maladaptive perfectionism among elder siblings, while Pearson’s product-moment correlation was used to examine the relationship between perceived stress and maladaptive perfectionism among elder daughters. Results indicated significant differences in perceived stress across sibling birth-order groups, F(2, 83) = 8.34, p< .001, with elder siblings reporting the highest mean perceived stress (M = 23.80, SD = 5.10), followed by middle siblings (M = 21.20, SD = 4.70) and younger siblings (M = 19.10, SD = 4.60). A significant difference was also observed in maladaptive perfectionism, F(2, 83) = 10.27, p< .001, with elder siblings reporting the highest mean score (M = 37.50, SD = 6.40), followed by middle siblings (M = 34.10, SD = 5.80) and younger siblings (M = 30.90, SD = 5.50). Among elder daughters, perceived stress was significantly and positively correlated with maladaptive perfectionism (r = .46, p< .001). Gender comparisons among elder siblings further indicated significant differences in perceived stress, t(46) = 2.05, p = .046, and maladaptive perfectionism, t(46) = 2.04, p = .047, with female elder siblings reporting higher scores on both measures than male elder siblings. The findings suggest that elder sibling status may be associated with comparatively greater psychological demands during adolescence, particularly in relation to perceived stress and maladaptive perfectionism