Social and Biological Factors related to Gender Expression in 3-Year-Olds Children

Background: Gender identity(GI) is the unified and persistent self-perception on the male-female spectrum, and its acquisition is a multifactorial process. GI is generally consolidated around 3-4 years. The Gender Identity Questionnaire for Children(GIQC) aims to assess GI in both clinical and non-clinical populations. Aim of the research is to evaluate GI in relation to social and biological factors. Methods: Single-center, prospective birth-cohort study enrolling born at term, appropriate for gestational age. The GIQC was administered to the parents at age 3. The scoring was performed trough the original coding scheme and the new coding scheme for non-clinical group based on 3 scales: Female Typical Behavior(FTB), Male typical Behavior(MTB), and Cross Gender(CG). Anthropometrics, anogenital distances and urinary hormones assessment was performed at birth, three, six and 36 months. Results: 86 children(males 53) participated. FTB, MTB, and CG scores differed significantly according to sex: boys (3.28±0.59) scored higher than girls (2.45±0.44) on MTB, while girls (3.41±0.75) scored higher than boys (1.92±0.61) on FTB. Girls (4.14±0.64) scored higher than boys (3.66±0.88) on CG scale. Within the whole sample the FTB scale showed a moderate negative correlation with MTB (r:-0.464,p<0.01) and a positive one with CG (r:0.377,p<0.001) in the female population. Correlations exist between MTB and Ano-Scrotal distance(AGD-AS) in males, and between MTB and Ano-Clitoris distance(AGD-AC) in females. Conclusion: Our findings confirm that by age 3, most children show that they express differentiated sextyped behavior according to the sex assigned at birth. Additionally, androgenization appears to play a role in gender identity development in males.