The second to fourth digit ratio in elite and non-elite female athletes

Abstract

Contests in the animal world to determine social status almost exclusively involve males, which points out that androgens may be indispensable in the development of competitive instincts. In animal studies, it has been shown that prenatal exposure to androgens may produce permanent changes toward more aggressive behavior in adulthood. Thus, there is a strong suspicion that women involved in competitive activities, such as sports, may have been exposed to high androgen levels in utero. There is strong evidence that the ratio between the second to fourth digits ratio (2D:4D ratio) correlates negatively with intrauterine androgen concentrations and could potentially be used as a marker for prenatal androgen exposure. Therefore, the purpose of our study was to test the hypothesis that women engaged in sports have lower 2D:4D ratio-a marker of high prenatal androgen exposure. We measured the 2D:4D ratios in elite and non-elite female athletes and compared them with female individuals not engaged in any sport activities. Our results showed that elite female athletes have significantly lower left hand 2D:4D ratios compared to the control group (P < 0.05). Therefore, we can speculate that low 2D:4D ratio may be a positive correlate of sports potential in females.

Correlation Analysis between the Ratios of Second Fingers to Fourth Fingers and Athletic Performance in Primary School Students

“…Similar research reports also show that male 2D: 4D than small females [2][3][4] [5].We know that 2D: 4D in the womb has been determined, 2D: 4D and testosterone levels and sperm counts were negatively; Positively correlated with the concentration of estradiol [6] [7] .Another study showed that male testosterone levels and right-hand 2D: 4D inverse relationship ,between women and men of luteinizing hormone (at right), estradiol (at right and left) and prolactin concentration (in right hand) and 2D : 4D into a positive relationship; Also through the gender, age, height and weight control, right-hand 2D: 4D still and luteinizing hormone and estradiol positive correlation relationship [8] .The report also explains the above documents present research on male 2D: 4D less than girls.…”

“…After retrieving a photo on your computer using Photoshop amount of arm length, close to the palm fingers from the crease to the top of the finger, measure out the righthand man of 2D and 4D length [1].20 Photos repeated random sampling volume 2 times, twice before and after the data are highly correlated (right r = 0.99, left r = 0.98). Calculated by SPSS 2D: 4D; right hand 2D: 4D, left hand 2D: 4D, left and right hand 2D: 4D average.…”

Digit ratios (2D:4D) determined by computer‐assisted analysis are more reliable than those using physical measurements, photocopies, and printed scans

“…Other investigators have used image analysis to determine 2D:4D from images obtained from flatbed scanners (Bailey and Hurd, 2005;de Bruin et al, 2006;McFadden and Shubel, 2002), radiographs (McIntyre et al, 2005, and digital photographs (Honekopp et al, 2006a;Pokrywka et al, 2005). Bailey and Hurd (2005) showed good intraobserver reliability when a single observer measured finger lengths in 10 subjects using computer-assisted image analysis on hand scans while McFadden and Shubel (2002) showed good interobserver reliability when three observers measured finger lengths using similar computer-based calipers on scanned images of the hand.…”

“…Bailey and Hurd (2005) showed good intraobserver reliability when a single observer measured finger lengths in 10 subjects using computer-assisted image analysis on hand scans while McFadden and Shubel (2002) showed good interobserver reliability when three observers measured finger lengths using similar computer-based calipers on scanned images of the hand. Investigations using digital photographs of hands pressed against a glass plate also showed good intra and interobserver reliability when using computer programs to measure finger lengths (Honekopp et al, 2006b;Pokrywka et al, 2005). However, it should be noted that the aforementioned studies only performed these small reliability tests to internally validate their observers' ability to measure finger lengths.…”

“…This is particularly important as effect sizes on 2D:4D are generally only moderate to low (Kemper and Schwerdtfeger, in press). At present, several methods have been used to assess 2D:4D including, physical measurements with calipers (Scutt and Manning, 1996), measurements from photocopies , scanned images (Bailey and Hurd, 2005), digital photographs (Pokrywka et al, 2005), radiographs (Paul et al, 2006; Robertson et al, 2007), inked handprints (Hall and Love, 2003), and scaled tubes (Nicholls et al, 2008). Each of these methods has limitations relating to feasibility and costs but in general, physical measurements, photocopies and scanned images are the most commonly used techniques.…”