Prenatal Androgen and Fine Motor Skills and Tactile Discrimination

Sex hormones experienced during prenatal exposure play a significant role in shaping certain lifelong characteristics by influencing both the physical and neurological development of individuals. The effects of these hormones, particularly on the developing nervous system, contribute to the emergence of behavioral and functional differences. Hand preference and certain behavioral traits in humans have been shown to be related to prenatal hormonal exposure. However, the development of these traits is not limited to hormonal influences alone, but is shaped by the interaction of genetic, environmental, and sociocultural factors. Due to the difficulties and risks of directly measuring prenatal hormone levels, biomarkers that indirectly reflect this exposure are used in research. In this context, the ratio of second to fourth finger length (2D:4D) is widely preferred because it is an easily applicable and non-invasive measurement. The 2D:4D ratio is generally lower in men than in women. 2D is more strongly influenced by prenatal estrogen, while 4D is more strongly influenced by prenatal testosterone; this occurs during the first trimester of intrauterine fetal development. However, whether the 2D:4D ratio is a reliable indicator of prenatal hormonal exposure is still a controversial issue in the literature. Therefore, examining the relationship between the 2D:4D ratio and various biological and functional characteristics remains important. To our knowledge, studies examining the relationship between the 2D:4D ratio, an indirect indicator of prenatal androgen exposure, and dexterity and tactile discrimination are limited. Accordingly, the planned study aims to evaluate the relationship between the 2D:4D ratio and fine motor skills and tactile discrimination in healthy young adults. It is hypothesized that prenatal hormonal exposure may indirectly shape finger morphology and receptor distribution by affecting skin and nervous system development, which may be a determining factor in tactile sensitivity and dexterity.