An Only Child versus a Child with a Sibling: Difference In Perfectionism and the Big Five Personality Traits

INTRODUCTION: Declining fertility and rising numbers of only children necessitate understanding their specific characteristics. The main objective of the present research study is to map the area of sibling constellations. It focuses on perfectionism and the Big Five personality traits.

METHODS: Online data were collected from 1,384 Slovak participants aged 15-74 (133 only children, 1,251 with siblings) using the Frost Multidimensional Perfectionism Scale (FMPS) and the Big Five Inventory (BFI 10). MannWhitney U tests compared groups, with effect sizes (AUC) calculated. Spearman’s correlation examined variable relationships.

RESULTS: Analysis of data showed that, within our research sample, an only child achieved significantly higher scores for neuroticism (p = 0.012) and perfectionism (p = 0.008) , while the agreeableness (p = 0.035) and conscientiousness (p = 0.014) scores were lower. No difference was observed for the personality traits of extraversion and openness. The strongest relation observed in the research, obtained through analysis of the correlations between the individual factors, was the positive relationship between neuroticism and concern over mistakes and doubts about actions (r = 0.48).

CONCLUSIONS: Given the significant differences in personality and perfectionism observed between only children and those with siblings, further research should explore the clinical implications of these findings.