The sex difference in dimensional communalities in Macaca nemestrina

Area of Science:

• Primatology
• Anthropology
• Comparative Anatomy

Background:

• Cranial, mandibular, and dental measurements are key indicators of skeletal development and variation.
• Previous studies have explored sex differences in skeletal morphology across various species.
• Understanding intr-individual variation is crucial for interpreting evolutionary trends and species-specific characteristics.

Purpose of the Study:

• To compare intr-individual correlations of skeletal measurements between adult male and female Macaca nemestrina.
• To investigate potential sex-based differences in developmental communalities within the species.
• To assess if higher female correlations represent a general biological trend, as observed in humans.

Main Methods:

• Lateral skull radiographs were used to obtain cranial, mandibular, and dental measurements.
• Intr-individual correlations were calculated for these measurements in both adult males and females.
• Statistical analysis was performed to compare correlation coefficients between the sexes.

Main Results:

• Intr-individual correlations were systematically higher in adult female Macaca nemestrina compared to adult males.
• The average difference in correlations ranged from 0.11 to 0.15, depending on the computational method.
• These findings indicate greater developmental and dimensional consistency in females.

Conclusions:

• Developmental and dimensional communalities are systematically higher in female Macaca nemestrina.
• This sex difference in skeletal measurement correlations supports a general biological principle observed in other species, including humans.
• The findings highlight a potential trend of greater developmental integration in females across primate species.