Digit Ratio as a Predictor of Language Development and Media Preferences in Kindergarten Children

Abstract

The role of prenatal testosterone (PT) in human behavior has increasingly been in the scope of psychoneuroendocrinological research in the recent years and has also been used to explain features of child (language) development. PT can be assessed by means of the so-called digit ratio 2D:4D, which is the ratio between the index (2nd digit) and the ring finger (4th digit). In the current paper, relations between PT, operationalized by means of 2D:4D, on the one hand and language development and media preferences (use of picture books) on the other hand in a sample of 190 three to four year-old children are reported. PT was significantly negatively associated with male as well as female performances in several language tests (e.g., language comprehension skills). In two analyses, 2D:4D was able to significantly distinguish between children of different developmental stages (normal vs. needing support vs. delayed). It was also found that, by trend, higher PT might be associated with less proneness to use picture books. It is concluded that PT is negatively associated with some features of language development as well as, potentially, with some early media preferences in pre-school age. Theoretical models of explanation and practical implications are discussed.