Association Between Estradiol and Human Aggression: A Systematic Review and Meta-Analysis

OBJECTIVE: Although several studies have examined the association between estradiol and human aggression, a consistent understanding of their correlation has yet to be established. This study aimed to investigate this relationship comprehensively. METHODS: We systematically searched five English databases (PubMed, Web of Science, EMBASE, Cochrane Library, and CINAHL) from their inception to June 5, 2023. Two authors independently screened publications and extracted data based on predefined inclusion and exclusion criteria. Statistical analyses were performed using Review Manager 5.4, and a random-effects model was used to pool the data. RESULTS: We identified 14 eligible studies comprising data from 1820 participants that met the inclusion criteria. This meta-analysis indicated a positive correlation between estradiol and human aggression, albeit a weak one. The pooled Fisher z value was 0.16 (95% confidence interval = 0.05–0.26; I(2) = 73%, p<.00001). Furthermore, we found that participants’ sex and age, the measures of aggression, and the literature quality might be sources of heterogeneity. CONCLUSIONS: Human aggression exhibited a weak positive correlation with estradiol concentration, whereas this relationship was influenced by participants’ sex and age, the measure of aggression used, and the quality assessment of the literature. Gaining a better understanding of the association between estradiol and aggression could aid in the identification of populations prone to aggression.