Relationships among Musical Aptitude, Digit Ratio and Testosterone in Men and Women

Jeremy C Borniger,Adeel Chaudhry,Michael P Muehlenbein,Kathleen A O’Connor

doi:10.1371/journal.pone.0057637

Abstract

Circulating adult testosterone levels, digit ratio (length of the second finger relative to the fourth finger), and directional asymmetry in digit ratio are considered sexually dimorphic traits in humans. These have been related to spatial abilities in men and women, and because similar brain structures appear to be involved in both spatial and musical abilities, neuroendocrine function may be related to musical as well as spatial cognition. To evaluate relationships among testosterone and musical ability in men and women, saliva samples were collected, testosterone concentrations assessed, and digit ratios calculated using standardized protocols in a sample of university students (N = 61), including both music and non-music majors. Results of Spearman correlations suggest that digit ratio and testosterone levels are statistically related to musical aptitude and performance only within the female sample: A) those females with greater self-reported history of exposure to music (p = 0.016) and instrument proficiency (p = 0.040) scored higher on the Advanced Measures of Music Audiation test, B) those females with higher left hand digit ratio (and perhaps lower fetal testosterone levels) were more highly ranked (p = 0.007) in the orchestra, C) female music students exhibited a trend (p = 0.082) towards higher testosterone levels compared to female non-music students, and D) female music students with higher rank in the orchestra/band had higher testosterone levels (p = 0.003) than lower ranked students. None of these relationships were significant in the male sample, although a lack of statistical power may be one cause. The effects of testosterone are likely a small part of a poorly understood system of biological and environmental stimuli that contribute to musical aptitude. Hormones may play some role in modulating the phenotype of musical ability, and this may be the case for females more so than males.

Highlights

Claude-Levi Strauss proclaimed ‘‘Since music is the only language with the contradictory attributes of being at once intelligible and untranslatable, the musical creator is a being comparable to the gods, and music itself the supreme mystery of the science of man’’ [1]
Elevated early androgen exposure due to congenital adrenal hyperplasia is associated with masculinized spatial abilities in females [8], but several studies have identified no relationships between male-biased spatial performance and adult circulating androgens [9] or digit ratios, a putative proxy for early androgens [8]
Others have reported elevations in testosterone associated with hormonal birth control [28], which would otherwise confound the results of the present study, we identified no statistical relationships between birth control status and testosterone (p = 0.939), Advanced Measures of Music Audiation (AMMA) (p = 0.11) and selfreported musical aptitude (p = 0.359)

Summary

Introduction

Claude-Levi Strauss proclaimed ‘‘Since music is the only language with the contradictory attributes of being at once intelligible and untranslatable, the musical creator is a being comparable to the gods, and music itself the supreme mystery of the science of man’’ [1]. It has been suggested that human musical ability, like bird song, may represent a trait evolved through the process of sexual selection, in response to mate choice [2]. Could musical ability have been, or continue to be, considered a trait which demonstrates survivability, intelligence, parental ability, ‘‘good genes,’’ or any other factors deemed important for mate choice? It is possible that there should be some sexual dimorphism in musical ability, and that this could be functionally linked to various biological factors. Hormones are related to spatial abilities in both men [4,5] and women [6,7] in complex ways. Hormones may be related to musical ability in interesting ways. How might testosterone be related to general musical capability, preference and exposure? And more importantly, why might this be so?

Methods

Results

Conclusion