Application of the Length of Index and Ring Fingers to Estimate the Stature.

INTRODUCTION: Stature contributes as a crucial element of an individual's physical appearance and can be instrumental in establishing their identity. In cases where the body is extensively mutilated, decomposed, or reduced to skeletal remains, stature becomes an essential component in identifying the unknown by means of measuring the skeletal remains. Its estimation relies on the principle that an individual's height has a definite and linear relationship with specific body parts and long bones. This process, together with assessing age, sex, and race constitutes the essential components of the anthropological protocol. Stature estimation can be accomplished through both anatomical and mathematical approaches. The present study clearly defines regression models for height estimation from finger lengths. The formula derived can prove particularly valuable in Medico-legal scenarios, as it can be applied effectively even when only a portion of the body is accessible. AIM: The purpose of the present study is to estimate the stature of individuals by measuring the length of the index and ring fingers. MATERIALS AND METHOD: The current study acquired three measurements, such as stature, right/left index finger length (RIFL/LIFL), and ring finger length (RFL), from 220 samples, including 110 males and 110 females, respectively, between the age groups of 20 and 60 years. RESULT: The application of the length of the index and ring finger in forensic investigations holds significance due to their potential as reliable predictors of an individual's height. According to the findings of the study, males showed significantly higher stature than females. A statistically significant correlation was also observed (p-value = 0) between stature and finger lengths (IFL, RFL) in both hands. The highest correlation coefficients were found for the left RFL (r = 0.688) in females and the LIFL (r = 0.552) in males. Additionally, males showed significantly longer index and RFL than females. Linear regression models for the estimation of stature from ring and index finger length were also derived successfully. CONCLUSION:  The results obtained from the present study exhibit potential use to evaluate the utility of measuring index and RFLs for determining stature and predicting the precision of regression models by employing those parameters. The models derived from this study can serve as corroborative evidence for identifying mutilated body parts or unknown remains.

Comparing Serum AMH, InhB, Testosterone Levels and Finger Length Ratio (2D/4D) of Male Children with Specific Learning Disorder and Controls.

Introduction: It has been suggested that inhibin B (InhB), Anti-Müllerian hormone (Müllerian-inhibiting substance, AMH) levels, and 2D/4D finger length ratios are related to sex differences in neurodevelopmental disorders. The aim of this study is to investigate the role of InhB, AMH levels, and 2D/4D finger length ratios in male children with specific learning disorder (SLD). Methods: The study included 38 male children diagnosed with SLD and 38 males of similar ages without SLD as the control group. Tests used in the evaluation were the Kiddie Schedule for Affective Disorders and Schizophrenia for School-Age Children-Present and Lifetime version, Specific learning disorder clinical observation battery, Wechsler Intelligence Scale for Children-Revised (WISC-R), and Conners' Parent Rating Scale. Revised: Short Form. Serum AMH, InhB, and Testosterone levels were measured using an enzyme-linked immunosorbent assay. Results: Male children diagnosed with SLD demonstrated significantly higher levels of serum InhB compared to controls (t= 2.59 p=0.009); both groups had similar levels of serum testosterone and AMH. The 2D/4D finger ratios in the SLD group were found to be lower than those in the control group (t= 2.92 p= 0.005). Serum InhB levels were positively correlated with WISC-R verbal scores (p= 0.003). Conclusion: Our findings suggest that serum InhB levels and the 2D/4D ratio, which is an indicator of prenatal testosterone exposure, may play a role in the male predominance of SLD.

Associations between Agility, the Relative Age Effect, Siblings, and Digit Ratio (D2:D4) in Children and Adolescents.

BACKGROUND: This study aims to analyze the influence of relative age effects, siblings, and digit ratio on the agility of children and adolescents. METHODS: The study included 283 children (9.54 ± 1.36 years) and 296 adolescents (14.68 ± 1.36 years) from four different schools. The analyzed variables included anthropometric data, the presence of siblings, relative age effect, and results from the 10 × 5 m shuttle run test. RESULTS: The findings indicated no significant association between agility and either the 2D:4D ratio or the relative age effect in both children and adolescents (p > 0.05). Additionally, having siblings did not have a notable impact on agility. Multiple regression analysis confirmed that relative age did not influence this lack of association (quarter of birth: p = 0.345, ß = 0.039; siblings: p = 0.100, ß = -0.069). However, boys showed higher performance than girls in the 10 × 5 m shuttle run test, and higher body mass index was related to lower agility. CONCLUSIONS: These findings contribute to existing knowledge on the relative effects of age and provide valuable information for physical education teachers on the influence of the 2D:4D ratio and the presence of siblings on the physical fitness of children and adolescents.

Biometrics of the Hand's Middle Finger to Determine Stature in Chilean University Students / Biometría del Dedo Medio de la Mano para Determinar Estatura en Estudiantes Universitarios Chilenos

SUMMARY: Biometrics and forensic osteology play a significant role in human identification, as the morphological uniqueness of every individual enables the differentiation and recognition of skeletal remains. Through meticulous analysis of human remains, it is possible to determine key demographic attributes such as stature, a significant parameter in the forensic identification process. This information is of practical relevance for the identification of individuals in contexts such as disasters, vehicular accidents, terrorist attacks, armed conflicts, and forensic investigations. The objective of this study was to determine the correlation between the hand's middle finger length and stature in a group of Chilean students. A total of 211 students of both sexes from La Araucanía region, Chile, participated in the study. After obtaining informed consent to participate voluntarily in the study, each individual underwent a general anthropometric examination, followed by a specific assessment of the length of the middle finger (MFL) of both hands. The results of the multiple linear regression analysis indicated a significant prediction of stature using the length of the right (R-MFL) and left (L-MFL) middle fingers, F (2, 207) = 79.80, p < 0.001. The equations for estimating stature based on the length of the middle fingers are as follows: for R-MFL, Stature = 91.265 + (8.092 x R-MFL), and for L-MFL, Stature = 83.967 + (8.889 x L-MF). Based on these results, it was found that the length of the middle finger of both hands is predictive of stature.

La biometría y la osteología forense desempeñan un papel relevante en la identificación humana, dado que la singularidad morfológica de cada individuo permite la diferenciación y reconocimiento de restos óseos. Mediante el análisis meticuloso de los restos humanos, es posible determinar atributos demográficos clave como la estatura, un parámetro significativo en el proceso de identificación forense. Esta información posee relevancia práctica para la identificación de personas en contextos de desastres, accidentes vehiculares, ataques terroristas, conflictos armados e investigaciones forenses. El objetivo de este estudio fue determinar la correlación entre la longitud del dedo medio de la mano con la estatura, en un grupo de estudiantes chilenos. Se evaluaron 211 estudiantes de ambos sexos de la región de La Araucanía, Chile. Tras obtener el consentimiento informado para participar voluntariamente en el estudio, se sometió a cada individuo a un examen antropométrico general, seguido de una evaluación específica de la longitud del dedo medio (MFL) de ambas manos. Los resultados del análisis de las regresiones lineales múltiples indicaron una significativa predicción de estatura utilizando la longitud de los dedos medios derecho (R-MFL) e izquierdo (L-MFL), F (2, 207) = 79.80, p < 0.001. Las ecuaciones para estimar estatura basados en la longitud de los dedos medios son las siguientes: para R-MFL, Stature = 91.265 + (8.092 x R-MFL) y para L-MFL, Stature = 83.967 + (8.889 x L- MF). A partir de estos resultados, se encontró que la longitud del dedo medio de ambos manos es predictora de estatura.

Diminished Anthropometric Measures and Other Associated Variables in a Sample of Violent Offenders: A Case-Control Study.

Background Predicting criminal behavior is a complex task due to its multidimensional nature. Nevertheless, health professionals and criminologists must consider individual criminogenic risk factors to provide reliable expert opinions. Physical traits have been a subject of scrutiny since the inception of biological positivism. Aim The main objective of this study is to analyze differences in individual characteristics between violent offenders and healthy volunteers to potentially identify predictors of criminal behavior. Methods We conducted a case-control study with a sample of inmates convicted of violent offenses and compared them to healthy volunteers. Anthropometrics, sociodemographic data, drug consumption, characteristics of the family nucleus, clinical background, and basic laboratory test results were collected. Quantitative data were tested for normality and homogeneity before applying the Mann-Whitney or T-Student tests, respectively. For categorical data, Pearson's chi-square test was used for associations, and the odds ratio was determined for the associated risk in drug abuse profiles. Results Among the male participants (N = 72), the inmate group (n = 41) showed significantly lower stature (mean height [m]: 1.7454 ± 0.0694 vs 1.6643 ± 0.0659, p < 0.001), a reduced left D2:D4 finger length ratio (mean ratio [cm]: 0.9638 ± 0.0572 vs 0.9380 ± 0.068cm, p < 0.05), and smaller anthropometric measurements, including armful (mean length [m]: 1.8080 ± 0.7690 vs 1.6582 ± 0.7250, p < 0.001), wrist (mean [cm]: 17.39 ± 1.10 vs 16.57 ± 1.84, p < 0.05), mid-upper arm (mean [cm]: 31.75 ± 3.79 vs 29.97 ± 3.79, p < 0.05), and head circumferences (mean [cm]: 58.43 ± 1.92 vs 55.39 ± 1.51, p < 0.001). Additionally, the inmate group exhibited shorter lower segments (mean [cm]: 102.67 ± 4.97 vs. 97.85 ± 5.04, p < 0.001) and plantar lengths (mean [cm]: 27.45 ± 1.25 vs. 26.78 ± 1.00, p < 0.05). Furthermore, this group displayed a higher risk of alcohol (OR = 4.4, p < 0.01), cocaine (OR = 3.36, p < 0.05), and benzodiazepine consumption (OR = 3.36, p < 0.05). Parental alcohol consumption (χ² = 12.66, p < 0.01) and the practice of Protestantism (χ² = 20.087, p < 0.001) were also associated with the inmate group. Conclusion Physical traits may be considered potential criminogenic risk factors, but larger studies are necessary to validate these findings. Future research should take into account physiological and psychological correlates to gain a comprehensive understanding of the complex relationship between physical traits and criminal behavior.

Association between index-ring finger length ratio and polymorphisms of 6 phalange-bone development related genes / 解剖学报

Objective To investigate the association of 13 single nucleotide polymorphism(SNP)sites in 6 phalange-bone development related genes[fibroblast growth factor receptor 2(FGFR2),indian hedgehog signaling molecule(IHH),Msh homeobox 1(MSX1),Runx family transcription factor 2(RUNX2),SRY-box transcription factor 9(SOX9),Wnt family member 5A(WNT5A)]with human index-ring finger length ratio(2D∶4D).Methods Digital cameras were used to take frontal photographs of the hands of 731 college students(358 males and 373 females)in Ningxia,and image analysis software was used to mark anatomical points and measure finger lengths of index(2th)and ring(4th);genotyping of 13 SNP sites(rs1047057,rs755793,rs41258305,rs3731881,rs3100776,rs12532,rs3821949,rs45585135,rs3749863,rs1042667,rs12601701,rs1829556,rs3732750)for 6 genes by multiplex PCR;One-Way ANOVA or independent sample t-test indirectly assessed the association between 2D∶4D and 13 SNP sites.Results Both left and right hand 2D∶4D were significantly higher in females than males in Ningxia college students(all P<0.01);no statistically significant differences in genotype and allele frequencies of the 13 SNP sites among different sexes(all P>0.05);among different sexes,male left hand 2D∶4D was significantly associated with the genotype of SOX9 gene rs12601701 site(P<0.05)and right hand 2D∶4D was significantly associated with the genotype of WNT5A gene rs1829556 site(P<0.05);the female right hand 2D∶4D was significantly associated with the MSX1 gene rs12532(P<0.01)and rs3821949(P<0.05)sites genotypes.Conclusion SOX9(rs12601701),WNT5A(rs1829556)and MSX1(rs12532 and rs3821949)gene polymorphisms may be associated with the formation of 2D∶4D in Ningxia population.

Digit Ratio (2D:4D) Is Not Associated with Alzheimer's Disease in the Elderly.

The development of Alzheimer's disease (AD) is influenced by sex hormones-estrogens and androgens in particular. However, the impact of prenatal sex hormone exposure is less clear; very few investigations have examined the relationship between the second-to-fourth digit length ratio (2D:4D), a putative proxy for the ratio of prenatal estrogens to androgens, and AD, with inconsistent results among the few that have. Therefore, we aimed to investigate this relationship using methodologically robust metrics. In a 2 (sex) × 4 (group) MANOVA incorporating 108 participants (30 AD patients, 19 patients with tauopathy but no amyloidopathy, 31 clinical and 28 healthy age- and education-matched controls), the effects of sex and group on the dependent variables right and left 2D:4D were examined. We also explored the association between 2D:4D and the severity of AD symptoms assessed via neuropsychological examination. We did not find any significant differences in the right- and left-hand 2D:4D between patients with AD and the other groups; no significant associations between 2D:4D and neuropsychological task performances were found in the dementia groups. The 2D:4D of healthy women was significantly lower than that of depressed women without AD, i.e., clinical controls, but not significantly different from depressed female patients with AD. This investigation does not support the role of 2D:4D in the development or severity of AD in general, but suggests a potential role of 2D:4D for depression in women. Future studies are warranted to clarify whether 2D:4D can distinguish between early- and late-onset depression in women.

Finger-Length Ratios and Sexual Orientation in Southern Spain: A Large Sample Study on Sex-Linked Personality and Cognitive Traits.

Some similarities between sex differences and sexual orientation differences, with gay men shifted in female-typical directions and lesbians shifted in male-typical directions, have been hypothesized to reflect the effects of prenatal androgen exposure. This report assessed sex-linked personality and cognitive traits in a Spanish sample of 1117 straight (i.e., heterosexual) and non-straight (i.e., non-heterosexual) men and women, using finger-length ratio (2D:4D) as an index of prenatal androgen exposure. Observed sex differences were in the expected direction: Measures of right-hand 2D:4D, left-hand 2D:4D, and anxiety were higher in straight women than men, whereas impulsivity, dominance, cognitive reflection, and mathematical proficiency were higher in straight men than women. Gay men proved to be shifted in a female-typical direction compared to straight men for right-hand 2D:4D, left-hand 2D:4D, anxiety, and cognitive reflection; they were intermediate for dominance and mathematics, and were shifted in a male-typical direction for impulsivity. Lesbians were shifted in a male-typical direction compared to straight women for left-hand 2D:4D, anxiety, cognitive reflection, and mathematics; and they were shifted in a highly female-typical direction for impulsivity and dominance (scoring lower than straight women). Observed sex-linked shifts in gay men and lesbians were larger for psychological traits that displayed larger sex differences, and smallest for impulsivity (which displayed the smallest sex difference). Evidence also suggested that sex-related measures were linked to 2D:4D in theoretically meaningful ways. In conclusion, this report suggests a plausible role of androgens as prenatal determinants of sex-linked personality and cognitive traits in straight and non-straight men and women.

Accuracy of predictive equations in guiding tracheal intubation depth in children: A prospective study.

BACKGROUND: Accurate insertion depth of endotracheal tube (ETT) in children has been predicted using the demographic variables, such as age, weight, and height. Middle finger length showed good correlation with ETT depth measurement in children aged 4-14 years. AIMS: The primary objective was to correlate the actual ETT insertion depth with the depth derived from middle finger length, age, weight, and height formulae in children aged 1-4 years. The secondary objective was to find the most accurate formula for prediction of ETT insertion depth. METHODS: This prospective parallel group study was done in 50 american society of anesthesiologists 1 or 2 children aged 1-4 years undergoing elective surgery under general anesthesia. Children with difficult airway, finger anomalies, or syndromic associations were excluded. Age, weight, height, and middle finger length of all children were measured. Depth of orally inserted uncuffed ETT and tracheal length was measured by fiberoptic bronchoscopy. The actual ETT depth was correlated with the depth calculated from different formulae. RESULTS: The mean middle finger length was 4.42 ± 0.50 cm, age was 2.64 ± 1.07 years, weight was 12.28 ± 2.84 kg, and height was 82.89 ± 16.23 cm. The mean tracheal length was 6.42 ± 0.96 cm. The mean depth of ETT was actual depth (12.89 ± 1.09 cm), middle finger depth (13.23 ± 1.53cm; p = .001; 95%CI 0.12-0.50), age-based depth 1(3.31 ± 0.53 cm; 95%CI 0.37-1.44; p = .001), weight-based depth (14.14 ± 1.42 cm; 95% CI 0.10-0.51; p = .004), and height-based depth (13.73 ± 0.94 cm; 95% CI 0.15-0.77; p = .004). Middle finger length and age-based formulae showed higher number of accurate placements (58% each). Weight- (74%) and height (64%)-derived formulae gave a higher number of distal ETT placements. CONCLUSION: Formulas based on the demographic variables and middle finger length showed good correlation with the actual ETT depth in children aged 1-4 years. The percentage of accurate ETT depth placements was higher with middle finger length and age-based formulae.

Does the 2nd and 4th digit ratio reflect prenatal androgen exposure?

OBJECTIVES:  The aim of our study was to describe the effect of prenatal testosterone exposure on 2D:4D in both sexes, and to determine whether this effect is mediated via the androgen receptor. In addition, the sex differences in lengths of 2D, 4D, and 2D:4D ratio were analyzed. BACKGROUND:  Clinical studies suggest a negative correlation between prenatal testosterone exposure and ratio of the lengths of the second and fourth digits (2D:4D). However, less is known about the underlying molecular mechanisms. METHODS:  Pregnant rats were treated with olive oil, testosterone, flutamide or testosterone with flutamide daily from the fourteenth day of pregnancy until delivery. The finger lengths of adult offspring were measured using both, digital scanning of the paws and µCT analysis of the phalanges. RESULTS:  None of the aforementioned methods revealed any effect of testosterone on 2D:4D. µCT measurements showed that prenatal hyperandrogenism in both sexes leads to shorter 2D compared to controls. Moreover, the testosterone treatment in males resulted in the shortening of 4D when compared to controls. CONCLUSION:  Prenatal hyperandrogenism leads to shorter lengths of 2D and 4D; however, it does not affect 2D:4D ratio. Whether other steroid hormones and/or testosterone metabolites affect the 2D:4D ratio requires further investigation (Tab. 5, Fig. 3, Ref. 32).

Differential Placing of Flexion Creases Contributes to Sex Differences in the Second-to-Fourth Digit Ratio (2D:4D).

The present research examined whether differential placing of the basal flexion creases contributes to the occurrence of sex differences in digit ratio (2D:4D) derived from palmar digit lengths. The ratio of palmar-to-dorsal digit length, a measure of the placing of the basal flexion crease in the finger, was derived for the digits 2 and 4 of the right hand in two independent samples (Study I: N = 100; Study II: N = 200), in accordance with discovery-replication sample approach. The results show that men have lower palmar-to-dorsal digit ratios than women, and this effect is significantly stronger for digit 2 than for digit 4. Thus, the present study supports the likelihood that differential placing of flexion creases in the digits contributes to the occurrence of sex differences in palmar 2D:4D. In addition (Study II), the measurement procedure assessing the placing of flexion creases was validated. In conclusion, this evidence highlights potential conceptual shortcomings and technical limitations in the measurement conventions and methods currently employed in the field of 2D:4D research.

Digit ratios and motor and health-related fitness in pre-adolescent females.

Background: Assessing different aspects of physical fitness in children whose abilities are undeveloped and their associations with second-to-fourth digit ratio (2D:4D) may better determine the potential athleticism of an individual.Aim: The purpose of the study was to examine relationships between the digit ratios and selected motor and health-related fitness parameters in a large sample of pre-adolescent females.Subjects and methods: Participants included 8-12 year old Iranian and Afghan girls. The length of the left and right second and fourth digits was measured by scanning and computer-assisted image analysis. Motor- and health-related fitness tests were evaluated.Results: No significant correlations were noted between right 2D:4D ratio and physical fitness components. Left 2D:4D and physical fitness components were not correlated, with the exception of handgrip strength (r = -0.193). However, right and left second digit lengths were negatively correlated with predicted VO2max (p ≤ 0.01). In addition, right-left 2D:4D was significantly negatively correlated with flexibility, and significantly positively correlated with height and body fat percentage.Conclusion: In contrast to previous investigations, it seems that left 2D:4D is a predictor of strength, but not aerobic exercise. It is suggested there may be a potential relationship between prenatal androgen exposure and high flexibility, low body fat percentage and the generation of muscular strength in pre-adolescent females.

Depressed female cynomolgus monkeys (Macaca fascicularis) display a higher second-to-fourth (2D:4D) digit ratio.

This research aimed to provide evidence of a relationship between digit ratio and depression status in the cynomolgus monkey (Macaca fascicularis). In stable cynomolgus monkey social groups, we selected 15 depressed monkeys based on depressive-like behavioral criteria and 16 normal control monkeys. All animals were video recorded for two weeks, with the duration and frequency of the core depressive behaviors and 58 other behaviors in 12 behavioral categories then evaluated via behavioral analysis. Finger lengths from the right and left forelimb hands of both groups were measured by X-ray imaging. Finger length and digit ratio comparisons between the two groups were conducted using Student's t-test. In terms of the duration of each behavior, significant differences emerged in "Huddling" and five other behavioral categories, including Ingestive, Amicable, Parental, Locomotive, and Resting. In addition to the above five behavioral categories, we found that depressed monkeys spent less time in parental and rubbing back and forth behaviors than the control group. Furthermore, the 4th fingers were significantly longer in the left and right hands in the control group relative to the depressed monkeys. The second-to-fourth (2D:4D) digit ratio in the left and right forelimb hands was significantly lower in the control group than that in the depressed group. Our findings revealed significant differences in finger lengths and digit ratios between depressed monkeys and healthy controls, which concords with our view that relatively high fetal testosterone exposure may be a protective factor against developing depressive symptoms (or that low fetal testosterone exposure is a risk factor).

Normalized second and fourth finger lengths in male and female partners and IVF cycle outcomes.

RESEARCH QUESTION: Hox genes are involved in limb formation during normal embryological development. Their modulation by circulating maternal oestrogens and androgens determines the length of the second and fourth fingers of the adult hand. Do these same intrauterine hormone levels also determine fertility outcomes in the adult? DESIGN: To study the association between the length of the second and fourth fingers of both partners undergoing IVF (as a surrogate of their previous intrauterine exposure to oestrogens and androgens) with treatment outcome after IVF, data corresponding to 256 IVF cycles were analysed. Finger length was normalized to the individual height. RESULTS: In the female partner, a longer normalized second finger length of the left (2DLN) hand, reflecting a high intrauterine exposure to oestrogens, was independently and significantly (P = 0.011) associated with obtaining at least one top-quality embryo in a multivariate model. Conversely, in the male partner a longer normalized fourth finger length of the left hand (4DLN), reflecting a high intrauterine exposure to androgens, was independently and significantly (P = 0.032) associated with obtaining at least one top-quality embryo in the same multivariate model. In the female partner, 2DLN was inversely and significantly (P = 0.01) associated with achievement of pregnancy. CONCLUSIONS: Intrauterine exposure to high levels of oestrogens and androgens in females and males, respectively, predisposes to the production of higher-quality embryos under in-vitro conditions during adulthood. Paradoxically, this also seems to result in a lower pregnancy rate.

2D:4D Ratio Differs in Ischemic Stroke: A Single Center Experience.

BACKGROUND: The index to ring finger length (2D:4D) ratio is a proxy biomarker for prenatal exposure of sex hormones. Sex hormones are associated with the pathogenesis of ischemic stroke. The purpose of the study was to demonstrate the association between 2D:4D and ischemic stroke. METHODOLOGY: This study retrospectively reviewed the data of 100 patients with first ever ischemic stroke between September, 2016 and June, 2017. The lengths of index finger and ring finger of both hands were measured using electronic calipers and calculated for 2D:4D ratios. Receive operating characteristic (ROC) mode was used to detect predicting performance of 2D:4D ratios for ischemic stroke. RESULTS: 2D:4D ratios in ischemic stroke patients were higher than controls in both hands (P < 0.05), except right 2D:4D ratio in females. The ROC analyses showed that the area under the curve (AUC) were 0.635 (95%CI: 0.527-0.743) for left 2D:4D ratio, and 0.647 for right (95%CI: 0.539-0.755) (P < 0.05). The AUC of left and right 2D:4D ratio in male were 0.667 (95%CI: 0.514-0.820) and 0.670 (95%CI: 0.519-0.822) (P < 0.05). In female, no significance were found in ROC analysis. And there were no correlation between 2D:4D value and stroke severity (P > 0.05). CONCLUSIONS: The current study indicated that the diagnostic value of 2D:4D ratio was limited in ischemic stroke. Further research is required to explore the role of it in screening ischemic stroke.

Finger Length Ratios of Identical Twins with Discordant Sexual Orientations.

A proposed marker of prenatal androgen exposure is the ratio of the index finger to ring finger (2D:4D). Within each sex, this ratio may be lower for those who were exposed to higher levels of androgens and become attracted to women, as compared to those who were exposed to lower levels of androgens and become attracted to men. We examined these patterns in identical twins with discordant sexual orientations. Because these twins are genetically identical, differences in prenatal androgen exposure, as reflected in their different finger length ratios, might contribute to their discordance. For 18 female twin pairs, non-straight (bisexual or lesbian) twins had significantly lower, or more masculinized, 2D:4D ratios than their straight co-twins, but only in the left hand. For 14 male pairs, non-straight twins had, contrary to our prediction, more masculinized finger length ratios than straight co-twins, but this difference was not significant. A reanalysis of present and previous data (Hall & Love, 2003; Hiraishi, Sasaki, Shikishima, & Ando, 2012) suggested that these patterns were robust. Furthermore, males had more masculinized 2D:4D ratios than females. This sex difference did not vary by sexual orientation.

The relationship of finger length ratios (2D: 4D) with quantitative, verbal talent and anthropometric parameters / La relación de las proporciones de la longitud del dedo (2D: 4D) con el parámetro cuantitativo, talento verbal y parámetros antropométricos

SUMMARY: The aim of this study were to investigate the relationship between 2D:4D finger length ratios (the ratio of the second finger length to the fourth finger length) of students from verbal and quantitative weighted fields, and to determine the correlation of these ratios with some anthropometric measurements. For this purpose; hand length, hand width, lengths of second and fourth finger and waist, hip and neck circumferences were taken from totally 398 (199 female, 199 male) students aged 17-25 years by using millimetric callipers and non-elastic standard measuring tape. Demographic data were also taken. Moreover, Body Mass Index (BMI) and 2D:4D finger length ratios of the study group were also calculated. When we investigated the 2D:4D ratios for right, left and dominant hands among verbal and quantitative talented individuals in female students, there were statistically significant differences for right and dominant hand (p=0.032; p=0.042, respectively). On the other hand, there was no difference for left hand in female participants (p>0.05). Furthermore, there were positive correlations with 2D:4D and weight (r=0.38, p<0.001), BMI (r=0.34, p=0.01) of the male students in verballyweighted field and with hip and waist circumferences in male students in quantitatively-weighted field (r=0.30; p=0.002; r=0.41, p<0.001). In male students in quantitatively-weighted fields, there was a weak and positive correlation with 2D:4D finger length ratios and neck circumferences on the left hand, and this relationship was statistically significant (r=0.21; p=0.032). And also, there were no statistically significant correlations between anthropometric measurements and 2D:4D ratios among the female students in quantitatively weighted field. Whereas there were positive correlations with 2D:4D finger length ratios and waist circumference in female students in verbally weighted field (r=0.24, p=0.018). We believe that the data obtained in this study will be a guide for career planning goals of persons according to their quantitative and verbal talents.

RESUMEN: El objetivo de este estudio consistió en investigar la relación entre índices de longitud del dedo (2D:4D) (es decir, la relación de la longitud del segundo dedo a la cuarta longitud del dedo) de los estudiantes de campos ponderados verbales y cuantitativos, para determinar la correlación de estas proporciones con algunas medidas antropométricas. Para este propósito, se consideraron las siguientes mediciones: longitud de la mano, ancho de la mano, circunferencia del segundo y cuarto dedo y circunferencia de cintura, cadera y cuello. Se examinaron 398 estudiantes (199 mujeres, 199 hombres) de 17-25 años de edad, usando pinzas milimétricas y cinta métrica estándar no elástica. También se tomaron datos demográficos. Además, se calcularon las proporciones de índice de masa corporal (IMC) y 2D:4D del grupo de estudio. Cuando investigamos las proporciones 2D:4D para manos derechas, izquierdas y dominantes entre individuos talentosos verbales y cuantitativos en mujeres, hubo diferencias estadísticamente significativas para la mano derecha y dominante (p = 0,032, p = 0,042, respectivamente). Por otro lado, no hubo diferencia para la mano izquierda en las mujeres (p> 0.05). Además, hubo correlaciones positivas con 2D:4D y peso (r = 0,38, p <0,001), IMC (r = 0,34, p = 0,01) de los hombres en el campo verbalmente ponderado y con circunferencias de cadera y cintura en hombres en campo ponderado cuantitativamente (r = 0,30, p = 0,002; r = 0.41, p <0,001). En los hombres, en campos cuantitativamente ponderados, hubo una correlación débil y positiva en 2D, relaciones de longitud de dedo 4D y circunferencias de cuello en la mano izquierda, y esta relación fue estadísticamente significativa (r = 0,21, p = 0,032). También, no hubo correlaciones estadísticamente significativas entre las medidas antropométricas y las proporciones 2D:4D entre las estudiantes en el campo cuantitativamente ponderado. Mientras que hubo correlaciones positivas con 2D:4D, índices de longitud del dedo y circunferencia de la cintura en las mujeres en el campo ponderado verbalmente (r = 0,24, p = 0,018). Creemos que los datos obtenidos en este estudio serán una guía para los objetivos de planificación de carrera de las personas de acuerdo con sus talentos cuantitativos y verbales.

Mindfulness-based Stress Reduction in Pregnancy: an App-Based Programme to Improve the Health of Mothers and Children (MINDFUL/PMI Study).

Unfavourable intrauterine environmental factors increase the risk of delivery complications as well as postpartum developmental and behavioural problems in children and adolescents with ongoing effects into older age. Biomarker studies show that maternal stress and the use of alcohol and tobacco during pregnancy are associated with a higher intrauterine testosterone exposure of the child. The antenatal testosterone load, in turn, is a risk factor for lasting adverse health effects which extend into adulthood. A 15-week, mindfulness-oriented, app-based programme for the reduction of stress as well as for the reduction of alcohol and tobacco use in pregnant women is established. In the monocentre, prospective, controlled, and investigator-blinded MINDFUL/PMI (Maternal Health and Infant Development in the Follow-up after Pregnancy and a Mindfulness Intervention) study, pregnant women carry out the programme. Its effect on antenatal testosterone exposure of the child is examined by assessing the index/ring finger length ratio and other biomarkers in the 1-year-old children. In addition, the programme's effects on self-regulation, the developmental status and the mental health of the children at the age of one year will be investigated. Additional aspects of the course of the pregnancy and delivery represent exploratory study objectives. This longitudinal study project is intended to improve the understanding of the impact of intrauterine environmental factors on early childhood development and health. Maternal stress as well as alcohol and tobacco use during pregnancy are modifiable factors and represent potential preventive targets.

2D:4D finger length ratio and radiographic hand osteoarthritis.

To evaluate the association between the index and ring finger's (2D:4D) length ratio with the prevalence and severity of radiographic hand osteoarthritis (OA). A population-based sample included 802 males (mean age 46.98 ± 17.10 years) and 738 females (mean age 48.65 ± 16.62 years) who had participated in a Chuvashian skeletal aging study. Age, sex, basic demographics, anthropometric data and X-rays of both hands were acquired. Each hand was visually classified on X-ray as either type 1-index finger longer than the ring finger; type 2-index and ring finger equal in length; or type 3-index finger shorter than the ring finger. Hand OA was defined by the number of affected joints (Kellgren-Lawrence score ≥ 2) in both hands and the sum total of Kellgren-Lawrence scores (total OA score). After comparing the OA variables of individuals with different finger length ratio types (after adjustment for age and BMI) significant differences were found only in females between finger ratio types of the right hand in a number of affected joints (F = 3.153, p = 0.043) and finger ratio types of the left (F = 3.330, p = 0.036) and right (F = 2.397, p = 0.047) hands of the total OA score. Females with type 3 ratios had the highest adjusted values of hand OA parameters. We found that finger length ratios are associated with hand OA parameters. Females with a type 3 finger length pattern showed significantly higher hand OA values than those with types 1 and 2.

Age of pubertal onset and 2nd to 4th digit ratios: Preliminary findings.

BACKGROUND: The second to fourth digit ratio (2D:4D) is used as a marker of prenatal sex hormone exposure. The aim of this study was to evaluate the possible relation between digit ratio and age of pubertal onset. METHODS: Participants were 321 men and 202 women aged between 18 and 28 at the time of assessment who self-reported their onset of puberty (i.e., age at first conscious ejaculation or menarche). Participants' right and left digit lengths were measured from hand scans. RESULTS: All groups of males, i.e., early, average, and late pubertal onset, had lower mean 2D:4D than the comparable female groups, regardless of the relative timing of their pubertal onset. Among the males, there was a significant difference in digit ratios between individuals who experienced early, average, and late onset of puberty. In the males, we observed a positive relationship between 2D:4D and age of pubertal onset for both right and left hands. There were no significant differences in 2D:4D among the three groups of female maturers. We observed no significant association between digit ratios and age at menarche. CONCLUSIONS: These data lend further support for using 2D:4D as a measure of prenatal androgen exposure.