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Prenatal Androgens (prenatal + androgen)

Distribution by Scientific Domains
Life Sciences66%

Selected Abstracts

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

AMERICAN JOURNAL OF HUMAN BIOLOGY, Issue 3 2009
Heather C. Allaway
Prenatal androgens influence the second to fourth digit ratio (2D:4D) of hands with men having lower ratios than women. Numerous methods are used to assess 2D:4D including, physical measurements with calipers, and measurements made from photocopies, scanned images, digital photographs, radiographs, and scaled tubes. Although each method appears relatively reliable, agreement upon a gold standard is necessary to better explore the putative effects of prenatal androgens. Our objective was to assess the level of intra and interobserver reliability when evaluating 2D:4D using four techniques: (1) physical measurements, (2) photocopies, (3) printed scanned images, and (4) computer-assisted image analysis. Physical measurements, photocopies, and printed scanned images were measured with Vernier calipers. Scanned images were also measured with computer-based calipers. Measurements were made in 30 men and 30 women at two different time points, by three experienced observers. Intraclass correlation coefficients were used to assess the level of reliability. Intraobserver reliability was best for computer-assisted (0.957), followed by photocopies (0.939), physical measurements (0.925), and printed scans (0.842; P = 0.015). Interobserver reliability was also greatest for computer-assisted (0.892), followed by photocopies (0.858), physical measurements (0.795), and printed scans (0.761; P = 0.001). Mean 2D:4D from physical measurements were higher than all other techniques (P < 0.0001). Digit ratios determined from computer-assisted, physical measurements, and printed scans were more reliable in men than women (P = 0.009, P = 0.017, and P = 0.012, respectively). In summary, 2D:4D determined from computer-assisted analysis yielded the most accurate and consistent measurements among observers. Investigations of 2D:4D should use computer-assisted measurements over alternate methods whenever possible. Am. J. Hum. Biol., 2009. © 2009 Wiley-Liss, Inc. [source]

Sex differences in juvenile rhesus macaque (Macaca mulatta) agonistic screams: Life history differences and effects of prenatal androgens

DEVELOPMENTAL PSYCHOBIOLOGY, Issue 4 2005
Michelle L. Tomaszycki
Abstract This study investigated sex differences in juvenile rhesus macaque (Macaca mulatta) vocal behavior during agonistic contexts, and the effects of prenatal androgens on these differences. A total of 59 subjects (5,8 per treatment group) received exogenous androgen (testosterone enanthate), an anti-androgen (flutamide) or vehicle injections (DMSO) for 30 or 35 days during the second (early) or third (late) trimester of pregnancy. An additional 19 unmanipulated controls were included in the analysis. Screams by juvenile males and females between the ages of 1 and 3 years were compared to the screams of adult female exemplars using a discriminant function analysis. Juvenile females produced more adult-female like screams than did juvenile males. Females exposed to androgen treatment late in gestation produced a more masculine pattern of screams. Flutamide treatment in males either early or late in gestation did not significantly affect scream production. Flutamide treatments in females late in gestation, however, masculinized scream production. Androgen treatments administered late in gestation hyper-masculinized male scream production. No sex differences in the contextual usage of screams emerged. These findings suggest that both life history differences and the early hormone environment contribute to sex differences in juvenile rhesus macaque vocal production. © 2005 Wiley Periodicals, Inc. Dev Psychobiol 47: 318,327, 2005. [source]

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

AMERICAN JOURNAL OF HUMAN BIOLOGY, Issue 3 2009
Heather C. Allaway
Prenatal androgens influence the second to fourth digit ratio (2D:4D) of hands with men having lower ratios than women. Numerous methods are used to assess 2D:4D including, physical measurements with calipers, and measurements made from photocopies, scanned images, digital photographs, radiographs, and scaled tubes. Although each method appears relatively reliable, agreement upon a gold standard is necessary to better explore the putative effects of prenatal androgens. Our objective was to assess the level of intra and interobserver reliability when evaluating 2D:4D using four techniques: (1) physical measurements, (2) photocopies, (3) printed scanned images, and (4) computer-assisted image analysis. Physical measurements, photocopies, and printed scanned images were measured with Vernier calipers. Scanned images were also measured with computer-based calipers. Measurements were made in 30 men and 30 women at two different time points, by three experienced observers. Intraclass correlation coefficients were used to assess the level of reliability. Intraobserver reliability was best for computer-assisted (0.957), followed by photocopies (0.939), physical measurements (0.925), and printed scans (0.842; P = 0.015). Interobserver reliability was also greatest for computer-assisted (0.892), followed by photocopies (0.858), physical measurements (0.795), and printed scans (0.761; P = 0.001). Mean 2D:4D from physical measurements were higher than all other techniques (P < 0.0001). Digit ratios determined from computer-assisted, physical measurements, and printed scans were more reliable in men than women (P = 0.009, P = 0.017, and P = 0.012, respectively). In summary, 2D:4D determined from computer-assisted analysis yielded the most accurate and consistent measurements among observers. Investigations of 2D:4D should use computer-assisted measurements over alternate methods whenever possible. Am. J. Hum. Biol., 2009. © 2009 Wiley-Liss, Inc. [source]

Grip strength and digit ratios are not correlated in women

AMERICAN JOURNAL OF HUMAN BIOLOGY, Issue 3 2007
Sari M. van AndersArticle first published online: 9 APR 200
Fink et al. (2006) have reported that men with higher grip strength (GS) have lower digit ratios (2D:4D), interpreting this as evidence for organizational effects of prenatal androgens on strength. In this study, I attempted to replicate their finding with 99 women. I found no evidence that digit ratios were associated with GS, suggesting that 2D:4D is not associated with GS in women. The null findings are discussed in light of gender and statistical considerations.Am. J. Hum. Biol. 19:437,439, 2007. © 2007 Wiley-Liss, Inc. [source]

Finger length ratios (2D:4D) in anthropoids implicate reduced prenatal androgens in social bonding

AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 3 2010
Emma Nelson
Abstract The second-to-fourth digit ratio (2D:4D) has been proposed as a biomarker reflecting prenatal androgen effects (PAE), such that individuals with lower ratios have experienced higher PAE than those with higher ratios. 2D:4D has been correlated with a number of sex-linked traits in humans such as aggression, promiscuity, and competitiveness. In addition, polygynous societies reportedly have lower 2D:4D (higher PAE) than more monogamous populations. This evidence suggests that PAE may be implicated in the development of sexually selected behaviors in humans. To place 2D:4D research into a broader context, we test the relationship between digit ratios and behavior across nonhuman anthropoids; polygynous species, with higher levels of intrasexual competition, should have more pronounced markers of PAE (lower 2D:4D) than pair-bonded species. Our results accord with those found in humans: 2D:4D is lower in polygynous species and higher (lower PAE) in pair-bonded species. Old World monkeys have low, and relatively invariant 2D:4D (high PAE), which is coupled with high levels of intrasexual competition. This contrasts with higher and more variable ratios in both great apes and New World monkeys. In addition, both male and female ratios decrease with increasing levels of intrasexual competition. Human ratios are intermediate between pair-bonded and more promiscuous hominoids. We propose that PAE may be involved in promoting species characteristic social behavior in anthropoids. Am J Phys Anthropol, 2010. © 2009 Wiley-Liss, Inc. [source]