Sex differences in intelligence on the SPM+ in Dhofar in the Sultanate of Oman

Following the Developmental Theory of Sex Differences, males and females have roughly the same IQ during childhood. However, because females enter puberty earlier their general IQ exceeds that of males during early adolescence, after which males enter puberty. By their late teens, males have a small IQ advantage. To test this model, we administered the SPM+ to a sample of 701 male and 705 female school students aged 10 to 19 years from different schools in the Dhofar Governorate in the Sultanate of Oman. Our results broadly validated Lynn's model, as males scores exceeded those of females from the age of 16 onwards. However, we note that there are also alternative explanations for our findings.