Adaptive Calibration of Life History Strategy in Türkiye: The Role of Childhood Unpredictability

Purpose: This study aimed to examine the impact of perceived early childhood environments (harshness and unpredictability) on life history strategies within Turkey and to adapt the Perceived Childhood Harshness and Unpredictability Scale (CHU) and the Arizona Life History Battery Short Form (K-SF-42) into Turkish. The central hypothesis, grounded in Life History Theory (LHT), was that unpredictability would be a stronger and independent predictor of fast life history strategies than harshness. Methods: A total of 635 volunteer participants aged 18–67 (M = 29.10, SD = 11.40; 74.5% female) were recruited via convenience sampling. Confirmatory factor analysis (CFA) and multi-group CFA were conducted to evaluate the psychometric properties and gender-based measurement invariance of both scales. Structural equation modeling (SEM) with full information maximum likelihood estimation was used to test the predictive pathways from childhood environmental factors to life history strategy and reproductive timing outcomes. Results: Both scales demonstrated acceptable model fit (CHU: CFI = .932; K-SF-42: CFI = .927) and high reliability (α and ω ≥ .74). Measurement invariance across gender was supported for both instruments. SEM results revealed that childhood unpredictability significantly and negatively predicted the General K factor (β = −.53, p < .001), whereas harshness did not reach significance in the structural model (β = .02, p = .746). Higher General K scores were associated with a later age at first sexual intercourse. Conclusion: The findings support the view that unpredictability constitutes a more decisive environmental signal than harshness in shaping life history strategies, validating core LHT predictions in a non-WEIRD cultural context. The Turkish adaptations of the CHU and K-SF-42 demonstrated sound psychometric properties, offering reliable tools for future cross-cultural research.