跳转到内容

用户:ElaineYuYC/沙盒

维基百科,自由的百科全书
无名指长于食指, 意味胎儿期时在子宫中暴露于较高的睾固酮环境

指长比为手指底部折痕到手指前端中点(如图)不同手指长度的比例。[1] 一些科学家认为食指无名指的指长比(2D:4D)受胎儿暴露在子宫雄激素(如睾酮)和雌激素不同程度结果所致,因而2D:4D被视为产前雄激素曝露量的天然测量指标,低2D:4D比率表示胎儿在子宫内暴露在较高浓度的雄激素环境。[2][3] The 2D:4D ratio is calculated by dividing the length of the index finger of the right hand by the length of the ring finger of the right hand. 较长的食指将导致指长比大于1,而较长的无名指将导致小于1的比率。

指长比2D:4D为两性异形,无论女性或男性,食指通常较短,但一般而言男性的指长差大于女性(意谓男性的2D:4D比率较女性小).[4]

部分研究已显示2D:4D与各种生理和行为特征之间具有关联性.[5]

指长比研究史

That a greater proportion of men have shorter index fingers than ring fingers than do women was noted in the scientific literature several times through the late 1800s,[6][7] with the statistically significant sex difference in a sample of 201 men and 109 women established by 1930,[8] after which time the sex difference appears to have been largely forgotten or ignored. In 1983 Dr Glenn Wilson英语Glenn Wilson (psychologist) of 伦敦国王学院 published a study examining the correlation between assertiveness in women and their digit ratio.[9] This was the first study to examine the correlation between digit ratio and a psychological trait within members of the same sex.[10] Wilson proposed that skeletal structure and personality were simultaneously affected by sex hormone levels in utero.[9] In 1998, John T. Manning and colleagues reported the sex difference in digit ratios was present in two-year-old children[11] and further developed the idea that the index was a marker of prenatal sex hormones. Since then research on the topic has burgeoned around the world.

A 2009 study in Biology Letters argues: "Sexual differences in 2D:4D are mainly caused by the shift along the common 异速生长 line with non-zero intercept, which means 2D:4D necessarily decreases with increasing finger length, and the fact that men have longer fingers than women,"[12] which may be the basis for the sex difference in digit ratios and/or any putative hormonal influence on the ratios.

A 2011 paper by Zhengui Zheng and Martin J. Cohn reports "the 2D:4D ratio in mice is controlled by the balance of androgen to estrogen signaling during a narrow window of digit development."[13] The formation of the digits in humans, in utero, is thought to occur by 13 weeks, and the bone-to-bone ratio is consistent from this point into an individual’s adulthood.[14] During this period if the fetus is exposed to androgens, the exact level of which is thought to be sexually dimorphic, the growth rate of the 4th digit is increased, as can be seen by analyzing the 2D:4D ratio of opposite sex dizygotic twins, where the female twin is exposed to excess androgens from her brother in utero, and thus has a significantly lower 2D:4D ratio.[15]

Importantly, there has been no correlation between the sex hormone levels of an adult and the individual’s 2D:4D,[16] which implies that it is strictly the exposure in utero that causes this phenomenon.

A major problem with the research on this topic comes from the contradiction in the literature as to whether the testosterone level in adults can be predicted by the 2D:4D ratio,[16] but male sexual traits that are stereotypically attributed to testosterone levels have been found in correlation with the 2D:4D. So there should be a correlation with one or the other but not both.

指长比的正态分布

A visualization of the distributions: Men (blue), women (green), and the whole population (red). Based on a population at University of Alberta and assuming normal distribution.

根据一份来自阿尔伯塔大学136名男性与137名女性的研究[17]

设其为正态分布, 2D:4D比率的95%信赖区间,男性落于0.889-1.005,而女性落于0.913-1.017 .

雄激素影响指长比的证据

患有先天性肾上腺增生症 (CAH)的女性具有较高浓度的雄激素, 她们有着较平均值低的2D:4D比.[18][19][20] 其它可能的生理影响包括阴蒂肥厚与阴道浅短.[21]

Males with CAH have more masculine (smaller) digit ratios than control males,[18][19] which also suggests that prenatal androgens affect digit ratios, since amniocentesis samples show that prenatal levels of testosterone are in the high normal range in males with CAH, while levels of the weaker androgen androstenedione英语androstenedione are several fold higher than in control males.[22][23][24] These measures indicate that males with CAH are exposed to greater prenatal concentrations of total androgens than are control males.

Digit ratio in men with 克氏综合征, who have reduced testosterone secretion throughout life compared to control males, are greater (i.e., more feminine) than in their fathers or control males.[25]

Digit ratio in men correlates with genetic variation in the 雄激素受体 gene.[26] Men with genes that produce androgen receptors that are less sensitive to testosterone (because they have more CAG repeats) have greater, more feminine, digit ratios. There are reports of a failure to replicate this finding.[27] However, men carrying an androgen receptor with more CAG repeats compensate for the less sensitive receptor by secreting more testosterone,[28] probably as a result of reduced negative feedback on gonadotropins. Thus, it is not clear that 2D:4D would be expected to correlate with CAG repeats, even if it accurately reflects prenatal androgen.

XY individuals with androgen insensitivity syndrome英语androgen insensitivity syndrome (AIS) due to a dysfunctional gene for the androgen receptor present as women and have feminine digit ratios on average, as would be predicted if androgenic hormones affect digit ratios. This finding also demonstrates that the sex difference in digit ratios is unrelated to the Y chromosome per se.[29]

The sex difference in 2D:4D is present before birth in humans,[30][31] which rules out any social influences that might affect digit growth differentially in the two sexes. Because all somatic sex differences in mammals to date have been found to be due to either androgenic masculinization or effects of the sex chromosomes, and as the AIS finding rules out a role for sex chromosomes in the sex difference in digit ratios, the prenatal sexual dimorphism also indicates that androgens act before birth to affect digit ratios. [来源请求]

The ratio of testosterone to 雌二醇 measured in 33 羊膜穿刺术 samples correlates with the child's subsequent 2D:4D ratio.[32]

In s, the ratio of the 2nd to 4th digit of the foot has been shown to be influenced by manipulations of testosterone in the .[33]

Studies in mice indicate that prenatal androgen acts primarily by promoting growth of the fourth digit.[34]

There is evidence that this reflects 胎儿 exposure to the 激素s 睾酮[35] and 雌激素.[来源请求]

Several studies present evidence that digit ratios are heritable.[36][37]

The level of estrogen in the amniotic fluid is not correlated with higher 2D:4D, and when examined researchers found no difference in estrogen levels between males and females.[38]

指长比影响的解释

目前尚不清楚为何产前激素会影响指长比. 还有其它类似特征的证据,例如耳声传射和手臂到躯干长度之比也显示了类似的效果. 同源异形基因 responsible for both digit and penis development[39] have been implicated in affecting these multiple traits (基因多效性). Direct effects of sex hormones on bone growth might be responsible, either by regulation of Hox genes in digit development or independently of such genes. Likewise, it is unclear why digit ratio on the right hand should be more responsive than that on the left hand, as is indicated by the greater sex difference on the right than the left.[40]

2D:4D的种族差异

Manning与其同事已表明,2D:4D比率在不同民族之间的差异很大。Manning等人发现汉族儿童有最高的2D:4D平均值(0.954±−0.032), 柏柏人次之(0.950±0.033), 然后是维吾尔族(0.946±0.037), 牙买加儿童的2D:4D平均比值最低(0.935±0.035).[41][42] 不同种族间的差异远大于性别差异; Manning说:“一个 波兰人跟一个芬兰人的差异,大于一个男人跟一个女人”[43]

It should be noted, however, that the errors associated with each given 2D:4D mean are such that there could in fact be no ethnic variation. For example, the ratio for Han children (0.954±−0.032) allows for a ratio as low as 0.922. The ratio for Jamaican children (0.935±0.035) allows for a ratio as high as 0.970. Research of higher accuracy is therefore necessary to determine whether or not there is ethnic variation in 2D:4D ratios.

2D:4D与特质间的关联

有些作者认为指长比与人生中的健康、行为,甚或 人类的性 有关联. 以下是一些非全面的清单,整理一些指长比与特质有关的发表.

低指长比

高指长比

生理与疾病
  • Increased risk of 前列腺癌 and prostate diseases in males.[44][45]
  • Slower utero fetal development in both sexes.[44]
  • Increased reproductive success in males.[46]
精神障碍
生理和竞争行为 运动中有较多的攻击性行为.[68]
  • Reduced performance in sports[69]
  • Reduced financial trading ability[70]
  • Right handedness skills[71] (inconclusive)[72]
认知与人格
管理
感官知觉
  • Smell perception[93]
  • Color perception[94]
  • Tactile perception[95]
性取向
  • Sexual preference for more masculine men among women[96] and gay men[109] with high digit ratio; a preference for a masculine facial type means a more "feminized" mindset.
  • Lesbians are more likely to be femme英语butch and femme and less likely to be butch英语butch and femme with a high digit ratio.[98][110] Identical female twins discordant for sexual orientation still show the difference (lesbian less than straight, on average) in digit ratio.[100][111]
  • Homosexuality for men, according to some studies.[99][107][112] Other studies have disputed this; some have shown that the digit ratio in homosexual men is similar to,[97][104][105][106][113] or lower than,[101][103][108] that of heterosexual men. One study concluded that differences are dependent on geographical variation, with gay men having lower or similar ratios to straight men in Europe, but higher or similar in the United States.[114] But this finding has been questioned in a meta-analysis including 18 studies, which suggested that ethnicity, rather than geography, explained the differences previously found in men of different sexual orientations. The meta-analysis concluded that there are no significant sexual orientation differences in digit ratio exist in men.[115]

跨性别女性的变性者

一份来自德国的研究发现,跨性别女性变性者有较顺性别男性高的指长比, but one that was comparable to cisgender women.[116]

指长比与发展

There is some evidence that 2D:4D ratio may also be indicative for human development and growth. Ronalds et al. (2002) showed that men who had an above average placental weight and a shorter neonatal crown-heel length had higher 2D:4D ratios in adult life.[117] Moreover, studies about 2D:4D correlations with face shape suggest that testosterone exposure early in life may set some constraints for subsequent development. Prenatal sex steroid ratios (in terms of 2D:4D) and actual chromosomal sex dimorphism were found to operate differently on human faces, but affect male and female face shape by similar patterns.[118] Fink et al. (2004) found that men with low (indicating high testosterone) and women with high (indicating high estrogen) 2D:4D ratios express greater levels of facial symmetry英语facial symmetry.[119] However, exposure to very high levels of testosterone and/or estrogen in the womb may have negative effects as well.

旧石器时代手模中的指长比

部分研究者正试图借由钻研史前欧洲和印尼的石洞壁画中旧石器时代的手模来研究当时的2D:4D.[120][121][122]

其它动物

  • Dennis McFadden与其同僚宣称某些人科动物(如大猩猩和黑猩猩)后肢指长比具有两性异形的现象。[99]
  • Emma Nelson和Susanne Shultz目前正在调查2D:4D与灵长类动物的交配战略和人类社会演化的关联性。[123]
  • Sexual dimorphism in hind limb 2D:4D has been demonstrated in mice by two studies by both John Manning and Marc Breedlove英语Marc Breedlove's research groups. There is some evidence to suggest that this effect is not seen in all mouse strains.[来源请求]
  • Nancy Burley's research group has demonstrated sexual dimorphism in zebra finches, and found a correlation between digit ratio in females and the strength of their preference for sexually selected traits in males.[来源请求]
  • Front limb D2:D3 has shown to be influenced by prenatal alcohol exposure in female rats.[来源请求]
  • Alžbeta Talarovičová and collaborators found in rats that elevated testosterone during the prenatal period can influence 4D length, the 2D:4D ratio, and open field motor activity.[124]
  • Peter L. Hurd英语Peter L. Hurd, Theodore Garland, Jr.英语Theodore Garland, Jr., and their students have examined hindlimb 2D:4D in lines of mice selectively bred for high voluntary wheel-running behavior (see experimental evolution英语experimental evolution). These high-runner mice exhibit increased 2D:4D. This apparent "feminization" is opposite to the relation seen between 2D:4D and physical fitness in human beings, and is difficult to reconcile with the idea that 2D:4D is a clear proxy for prenatal androgen exposure in mice. The authors suggest that 2D:4D may more accurately reflect effect of glucocorticoids or other factors that regulate any of various genes.[125]

参见

参考文献

  1. ^ T M Mayhew, L Gillam, R McDonald, and F J P Ebling. Human 2D (index) and 4D (ring) digit lengths: their variation and relationships during the menstrual cycle. Journal of Anatomy. November 2007, 211 (5): 630–638. PMC 2375787可免费查阅. PMID 17764524. doi:10.1111/j.1469-7580.2007.00801.x. 
  2. ^ Zheng, Zhengui; Cohn, Martin J. Developmental basis of sexually dimorphic digit ratios. Proceedings of the National Academy of Sciences. 2011-09-27, 108 (39): 16289–16294. ISSN 0027-8424. PMC 3182741可免费查阅. PMID 21896736. doi:10.1073/pnas.1108312108. 
  3. ^ Hönekopp, Johannes; Bartholdt, Luise; Beier, Lothar; Liebert, Andreas. Second to fourth digit length ratio (2D:4D) and adult sex hormone levels: New data and a meta-analytic review. Psychoneuroendocrinology. 2007-01-01, 32 (4): 313–21. PMID 17400395. doi:10.1016/j.psyneuen.2007.01.007. 
  4. ^ Manning, John T. Digit Ratio: A Pointer to Fertility, Behavior, and Health. Rutgers University Press. 2002-01-01. ISBN 9780813530307. 
  5. ^ Wlodarski, R.; Manning, J.; Dunbar, R. I. M. Stay or stray? Evidence for alternative mating strategy phenotypes in both men and women. Biology Letters. 4 February 2015, 11 (2): 20140977–20140977. doi:10.1098/rsbl.2014.0977. 
  6. ^ Ecker A. Einige Bemerkungen über einen Schwankenden Charakter in den Hand des Menschen[Some remarks about a varying character in the hand of humans]. Archiv für Anthropologie. 1875, 8: 68–74. 
  7. ^ Baker F. Anthropological notes on the human hand. The American Anthropologist. 1888, 1: 51–75. doi:10.1525/aa.1888.1.1.02a00040. 
  8. ^ George R. Human finger types. Anatomical Record. 1930, 46 (2): 199–204. doi:10.1002/ar.1090460210. 
  9. ^ 9.0 9.1 9.2 Wilson, Glenn D. Finger-length as an index of assertiveness in women. Personality and Individual Differences. 1983, 4 (1): 111–2. doi:10.1016/0191-8869(83)90061-2. 
  10. ^ Wilson, G. Fingers to feminism: The rise of 2D:4D. Quarterly Review. 2010, 4: 25–32. 
  11. ^ Manning JT, Scutt D, Wilson J, Lewis-Jones DI; Scutt; Wilson; Lewis-Jones. The ratio of 2nd to 4th digit length: a predictor of sperm numbers and concentrations of testosterone, luteinizing hormone and oestrogen. Hum Reprod. 1998, 13 (11): 3000–3004. PMID 9853845. doi:10.1093/humrep/13.11.3000. 
  12. ^ Kratochvíl L, Flegr J; Flegr. Differences in the 2nd to 4th digit length ratio in humans reflect shifts along the common allometric line. Biology Letters. October 2009, 5 (5): 643–6. PMC 2781964可免费查阅. PMID 19553247. doi:10.1098/rsbl.2009.0346. 
  13. ^ Zhengui Z., Cohn M. J.; Cohn. Developmental basis of sexually dimorphic digit ratios. Proceedings of the National Academy of Sciences of the United States of America. 2011, 108 (39): 16289–16294. PMC 3182741可免费查阅. PMID 21896736. doi:10.1073/pnas.1108312108. 
  14. ^ Garn S. M., Burdi A. R., Babler W. J., Stinson S.; Burdi; Babler; Stinson. Early prenatal attainment of adult metacarpal-phalangeal rankings and proportions. American Journal of Physical Anthropology. 1975, 43 (3): 327–332. PMID 1211429. doi:10.1002/ajpa.1330430305. 
  15. ^ van Anders SM, Vernon PA, Wilbur CJ; Vernon; Wilbur. Finger-length ratios show evidence of prenatal hormone-transfer between opposite-sex twins. Hormones and Behavior. 2006, 49 (3): 315–9. PMID 16143332. doi:10.1016/j.yhbeh.2005.08.003. 
  16. ^ 16.0 16.1 Hönekopp Johannes, Bartholdt Luise, Beier Lothar, Liebert Andreas; Bartholdt; Beier; Liebert. Second to fourth digit length ratio (2D:4D) and adult sex hormone levels: New data and a meta-analytic review. Psychoneuroendocrinology. 2007, 32 (4): 313–321. PMID 17400395. doi:10.1016/j.psyneuen.2007.01.007. 
  17. ^ 17.0 17.1 Bailey AA, Hurd PL; Hurd. Finger length ratio (2D:4D) correlates with physical aggression in men but not in women. Biological Psychology. March 2005, 68 (3): 215–22. PMID 15620791. doi:10.1016/j.biopsycho.2004.05.001. 简明摘要LiveScience英语LiveScience (2 March 2005). 
  18. ^ 18.0 18.1 Brown WM, Hines M, Fane BA, Breedlove SM; Hines; Fane; Breedlove. Masculinized finger length patterns in human males and females with congenital adrenal hyperplasia (PDF). Hormones and Behavior. December 2002, 42 (4): 380–6. PMID 12488105. doi:10.1006/hbeh.2002.1830. 
  19. ^ 19.0 19.1 Okten A, Kalyoncu M, Yariş N; Kalyoncu; Yariş. The ratio of second- and fourth-digit lengths and congenital adrenal hyperplasia due to 21-hydroxylase deficiency. Early Human Development英语Early Human Development. December 2002, 70 (1–2): 47–54. PMID 12441204. doi:10.1016/S0378-3782(02)00073-7. 
  20. ^ Ciumas C, Lindén Hirschberg A, Savic I.; Lindén Hirschberg; Savic. High fetal testosterone and sexually dimorphic cerebral networks in females. Cereb Cortex. 2009, 19 (5): 1164–72. PMID 18854582. doi:10.1093/cercor/bhn160. 
  21. ^ Richard D. McAnulty, M. Michele Burnette (2006) Sex and sexuality, Volume 1, Greenwood Publishing Group, p.165
  22. ^ Pang S, Levine LS, Cederqvist LL, Fuentes M, Riccardi VM,Holcombe JH, Nitowsky HM, Sachs G, Anderson CE, Duchon MA,Owens R, Merkatz I, New MI; Levine; Cederqvist; Fuentes; Riccardi; Holcombe; Nitowsky; Sachs; Anderson; Duchon; Owens; Merkatz; New. Amniotic fluid concentrations of delta5 and delta4 steroids in fetuses with congenital adrenal hyperplasia. J Clin Endocrinol Metab. 1980, 51 (2): 223–229. PMID 6447160. doi:10.1210/jcem-51-2-223. 
  23. ^ Dorr, H. G., and Sippell, W. G. Prenatal dexamethasone treatment in pregnancies at risk for congenital adrenal hyperplasia due to 21-hydroxylase deficiency: Effect on midgestational amniotic fluid steroid levels. J. Clin. Endocrinol. Metab. 1993, 76 (1): 117–120. PMID 8421074. doi:10.1210/jc.76.1.117. 
  24. ^ LWudy, S. A., Dorr, H. G., Solleder, C., Djalali, M., and Homoki, J. Profiling steroid hormones in amniotic fluid of midpregnancy by routine stable isotope dilution/gas chromatography mass spectrometry: Reference values and concentrations in fetuses at risk for 21-hydroxylase deficiency. J. Clin. Endocrinol. Metab. 1999, 84 (8): 2724–2728. PMID 10443667. doi:10.1210/jc.84.8.2724. 
  25. ^ Manning JT, Kilduff LP, Trivers R; Kilduff; Trivers. Digit ratio (2D:4D) in Klinefelter's syndrome. Andrology. 2013, 1 (1): 94–99. PMID 23258636. doi:10.1111/j.2047-2927.2012.00013.x. 
  26. ^ Manning, John T.; Bundred, Peter E.; Newton, Darren J.; Flanagan, Brian F. The second to fourth digit ratio and variation in the androgen receptor gene. Evolution and Human Behavior. 2003, 24 (6): 399–405. doi:10.1016/S1090-5138(03)00052-7. 
  27. ^ Hampson E, Sankar JS; Hampson. Re-examining the Manning hypothesis: androgen receptor polymorphism and the 2D:4D ratio. Evol Hum Behav. 2012, 33 (4): 557–561. PMID 22728214. doi:10.1016/j.genm.2012.05.001. 
  28. ^ Crabbe P, Bogaert V, De Bacquer D, Goemaere S, Zmierczak H, Kaufman JM.; Bogaert; De Bacquer; Goemaere; Zmierczak; Kaufman. Part of the interindividual variation in serum testosterone levels in healthy men reflects differences in androgen sensitivity and feedback set point: contribution of the androgen receptor polyglutamine tract polymorphism. J Clin Endocrinol Metab. 2007, 92 (9): 3604–10. PMID 17579205. doi:10.1210/jc.2007-0117. 
  29. ^ Berenbaum SA, Bryk KK, Nowak N, Quigley CA, Moffat S; Bryk; Nowak; Quigley; Moffat. Fingers as a Marker of Prenatal Androgen Exposure. Endocrinology. November 2009, 150 (11): 5119–24. PMC 2775980可免费查阅. PMID 19819951. doi:10.1210/en.2009-0774. 
  30. ^ Malas MA, Dogan S, Evcil EH, Desdicioglu K.; Dogan; Evcil; Desdicioglu. Fetal development of the hand, digits and digit ratio (2D:4D). Early Hum Dev. 2006, 82 (7): 469–475. PMID 16473482. doi:10.1016/j.earlhumdev.2005.12.002. 
  31. ^ Galis F, Ten Broek CM, Van Dongen S, Wijnaendts LC; Ten Broek; Van Dongen; Wijnaendts. Sexual Dimorphism in the Prenatal Digit Ratio (2D:4D). Arch Sex Behav. 2009, 38 (1): 57–62. PMC 2811245可免费查阅. PMID 19301112. doi:10.1007/s10508-009-9485-7. 
  32. ^ Lutchmaya S, Baron-Cohen S, Raggatt P, Knickmeyer R, Manning JT; Baron-Cohen; Raggatt; Knickmeyer; Manning. 2nd to 4th digit ratios, fetal testosterone and estradiol. Early Human Development. April 2004, 77 (1–2): 23–8. PMID 15113628. doi:10.1016/j.earlhumdev.2003.12.002. 
  33. ^ 33.0 33.1 Romano M, Leoni B, Saino N; Leoni; Saino. Examination marks of male university students positively correlate with finger length ratios (2D:4D). Biological Psychology. February 2006, 71 (2): 175–82. PMID 15978716. doi:10.1016/j.biopsycho.2005.03.006. 
  34. ^ Zheng Z, Cohn MJ; Cohn. Developmental basis of sexually dimorphic digit ratio. PNAS. 2011, 108 (39): 16289–94. PMC 3182741可免费查阅. PMID 21896736. doi:10.1073/pnas.1108312108. 
  35. ^ McIntyre MH. The use of digit ratios as markers for perinatal androgen action. Reproductive Biology and Endocrinology. 2006, 4: 10. PMC 1409789可免费查阅. PMID 16504142. doi:10.1186/1477-7827-4-10. 
  36. ^ Paul SN, Kato BS, Hunkin JL, Vivekanandan S, Spector TD; Kato; Hunkin; Vivekanandan; Spector. The Big Finger: the second to fourth digit ratio is a predictor of sporting ability in women. British Journal of Sports Medicine. December 2006, 40 (12): 981–3. PMC 2577466可免费查阅. PMID 17008344. doi:10.1136/bjsm.2006.027193. 
  37. ^ Gobrogge, K.L., S.M.Breedlove & K.L.Klump; Breedlove; Klump. Genetic and environmental influences on 2d:4d finger length ratios: a study of monozygotic and dizygotic male and female twins. Archives Sexual Behavior. 2008, 37 (1): 112–118. PMID 18074216. doi:10.1007/s10508-007-9272-2. 
  38. ^ Lutchmaya S., Baron-Cohen S., Raggatt P., Knickmeyer R., Manning J. T.; Baron-Cohen; Raggatt; Knickmeyer; Manning. 2nd To 4th Digit Ratios, Fetal Testosterone and Estradiol. Early human development. 2004, 77 (1–2): 23–8. PMID 15113628. doi:10.1016/j.earlhumdev.2003.12.002. 
  39. ^ Dickman S. HOX gene links limb, genital defects. Science. Mar 1997, 275 (5306): 1568–9. PMID 9072822. doi:10.1126/science.275.5306.1568. 
  40. ^ Honekopp J, Watson S; Watson. Meta-analysis of digit ratio 2D:4D shows greater sex difference in the right hand. American Journal of Human Biology. 2010, online (5): 619–30. PMID 20737609. doi:10.1002/ajhb.21054. 
  41. ^ Manning, J. T.; Barley, L.; Walton, J.; et al. The 2nd:4th digit ratio, sexual dimorphism, population differences, and reproductive success. evidence for sexually antagonistic genes?. Evolution and Human Behavior. May 2000, 21 (3): 163–183. PMID 10828555. doi:10.1016/S1090-5138(00)00029-5. 
  42. ^ Manning JT, Stewart A, Bundred PE, Trivers RL; Stewart; Bundred; Trivers. Sex and ethnic differences in 2nd to 4th digit ratio of children. Early Human Development. November 2004, 80 (2): 161–8. PMID 15500996. doi:10.1016/j.earlhumdev.2004.06.004. 
  43. ^ Terrance, J.; Williams, Michelle E. Pepitone, Scott E. Christensen, Bradley M. Cooke, Andrew D. Huberman, Nicholas J. Breedlove, Tessa J. Breedlove, Cynthia L. Jordan and S. Marc Breedlove. Finger-length ratios and sexual orientation. Nature. 30 March 2000, 404 (6777): 455–456. PMID 10761903. doi:10.1038/35006555. , available on-line at Finger-length ratios and sexual orientation. University of Nebraska-Lincoln.  (quoted from New Scientist)
  44. ^ 44.0 44.1 44.2 Manning, John T. Digit Ratio: A Pointer To Fertility, Behavior And Health. New Brunswick: Rutger University Press. 2002: 65–68. ISBN 0813530296. 
  45. ^ Sudhakar, Hanumanthaiah Honnamachanahalli; Manjunatha, Revanna; Madhusudhana, Heragu Rangegowda. Relationship Between Second to Fourth Digit Ratios and Benign Prostatic Hyperplasia in Aging Men. Journal of Clinical and Diagnostic Research : JCDR. 2015-05-01, 9 (5): PC01–PC03. ISSN 2249-782X. PMC 4484107可免费查阅. PMID 26155515. doi:10.7860/JCDR/2015/11992.5937. 
  46. ^ 46.0 46.1 Manning, J. T.; Barley, L.; Walton, J.; Lewis-Jones, D. I.; Trivers, R. L.; Singh, D.; Thornhill, R.; Rohde, P.; Bereczkei, T. The 2nd:4th digit ratio, sexual dimorphism, population differences, and reproductive success: evidence for sexually antagonistic genes?. Evolution and Human Behavior. 2000-05-01, 21 (3): 163–183. doi:10.1016/S1090-5138(00)00029-5. 
  47. ^ Manning JT, Scutt D, Wilson J, Lewis-Jones DI; Scutt; Wilson; Lewis-Jones. The ratio of 2nd to 4th digit length: a predictor of sperm numbers and concentrations of testosterone, luteinizing hormone and oestrogen. Human Reproduction. November 1998, 13 (11): 3000–4. PMID 9853845. doi:10.1093/humrep/13.11.3000. 
  48. ^ Manning JT, Bundred PE. The ratio of second to fourth digit length and age at first myocardial infarction in men: a link with testosterone?. British Journal of Cardiology. 2001, 8 (12): 720–3. ISSN 0969-6113. 
  49. ^ Fink B, Manning JT, Neave N; Manning; Neave. The 2nd-4th digit ratio (2D:4D) and neck circumference: implications for risk factors in coronary heart disease. International Journal of Obesity. April 2006, 30 (4): 711–4. PMID 16261185. doi:10.1038/sj.ijo.0803154. 
  50. ^ Walsh, Fergus. Index finger length prostate cancer clue. BBC News. 1 December 2010 [1 December 2010]. 
  51. ^ Ronalds G, Phillips DIW, Godfrey KM, Manning JT. The ratio of second to fourth digit lengths: a marker of impaired fetal growth? Early Hum. Dev. 2002;68:21–6.
  52. ^ Klimek M, Galbarczyk A, Nenko I, Alvarado LC, Jasienska G.; Galbarczyk; Nenko; Alvarado; Jasienska. Digit ratio (2D:4D)as an indicator of body size, testosterone concentration and number of children in human males. Ann Hum Biol. 2014, 41: 1. PMID 24766144. doi:10.3109/03014460.2014.902993. 
  53. ^ McFadden, D., Westhafer, J.G., Pasanen, E.G., Carlson, C.L., and Tucker, D.M. Physiological evidence of hypermasculinization in boys with the inattentive subtype of attention-deficit/hyperactivity disorder (ADHD). Clinical Neuroscience Research. 2005, 5 (5–6): 233–245. doi:10.1016/j.cnr.2005.09.004. 
  54. ^ Stevenson JC, Everson PM, Williams DC, Hipskind G, Grimes M, Mahoney ER.; Everson; Williams; Hipskind; Grimes; Mahoney. Attention deficit/hyperactivity disorder (ADHD) symptoms and digit ratios in a college sample. Am J Hum Biol. 2007, 19 (1): 41–50. PMID 17160985. doi:10.1002/ajhb.20571. 
  55. ^ Martel, M.M, K.L.Gobrogge, S.M.Breedlove & J.T.Nigg; Gobrogge; Breedlove; Nigg. Masculinized Finger-Length Ratios of Boys, but Not Girls, Are Associated With Attention-Deficit/Hyperactivity Disorder. Behavioral Neuroscience. 2008, 122 (2): 273–281. PMC 2902868可免费查阅. PMID 18410167. doi:10.1037/0735-7044.122.2.273. 
  56. ^ Martel, M.M. Conscientiousness as a mediator of the association between masculinized finger-length ratios and attention-deficit/hyperactivity disorder (ADHD). J Child Psychol Psychiatry. 2009, 50 (7): 790–798. PMID 19298468. doi:10.1111/j.1469-7610.2009.02065.x. 
  57. ^ Manning JT, Baron-Cohen S, Wheelwright S, Sanders G; Baron-Cohen; Wheelwright; Sanders. The 2nd to 4th digit ratio and autism. Developmental Medicine and Child Neurology. March 2001, 43 (3): 160–4. PMID 11263685. doi:10.1017/S0012162201000317. 
  58. ^ 58.0 58.1 Quinton, Stephanie Jane; Smith, April Rose; Joiner, Thomas. The 2nd to 4th digit ratio (2D:4D) and eating disorder diagnosis in women. Personality and individual differences. 2011-09-01, 51 (4): 402–405. ISSN 0191-8869. PMC 3134962可免费查阅. PMID 21765573. doi:10.1016/j.paid.2010.07.024. 
  59. ^ 59.0 59.1 Quinton, Stephanie Jane; Smith, April Rose; Joiner, Thomas. The 2 to 4 digit ratio (2D:4D) and eating disorder diagnosis in women. Personality and Individual Differences. 2011-09-01, 51 (4): 402–405. ISSN 0191-8869. PMC 3134962可免费查阅. PMID 21765573. doi:10.1016/j.paid.2010.07.024. 
  60. ^ 60.0 60.1 Carré, Justin M.; Ortiz, Triana L.; Labine, Brandy; Moreau, Benjamin J. P.; Viding, Essi; Neumann, Craig S.; Goldfarb, Bernard. Digit ratio (2D:4D) and psychopathic traits moderate the effect of exogenous testosterone on socio-cognitive processes in men. Psychoneuroendocrinology. 2015-12-01, 62: 319–326. ISSN 1873-3360. PMID 26356040. doi:10.1016/j.psyneuen.2015.08.023. 
  61. ^ Kornhuber, Johannes; Erhard, Gabriele; Lenz, Bernd; Kraus, Thomas; Sperling, Wolfgang; Bayerlein, Kristina; Biermann, Teresa; Stoessel, Christina. Low Digit Ratio 2D∶4D in Alcohol Dependent Patients. PLoS ONE. 2011-04-25, 6 (4): e19332. PMC 3081847可免费查阅. PMID 21547078. doi:10.1371/journal.pone.0019332. 
  62. ^ Bailey, A. & Hurd, P., Allison A.; Hurd, Peter L. Depression in men is associated with more feminine finger length ratios. Personality and Individual Differences. 2005, 39 (4): 829–836. doi:10.1016/j.paid.2004.12.017. 
  63. ^ Arató M, Frecska E, Beck C, An M, Kiss H; Frecska; Beck; An; Kiss. Digit length pattern in schizophrenia suggests disturbed prenatal hemispheric lateralization. Progress in Neuro-psychopharmacology & Biological Psychiatry. January 2004, 28 (1): 191–4. PMID 14687873. doi:10.1016/j.pnpbp.2003.09.020. 
  64. ^ Blanchard, A.; Lyons, M. An Investigation into the Relationship between Digit Length Ratio and Psychopathy. British Journal of Forensic Practice. May 2010, 12 (2): 23–31. doi:10.5042/bjfp.2010.0183. 
  65. ^ Kornhuber J, Erhard G, Lenz B, Kraus T, Sperling W, Bayerlein K, Biermann T, Stoessel C; Erhard; Lenz; Kraus; Sperling; Bayerlein; Biermann; Stoessel. Zhang, Xiang Yang , 编. Low Digit Ratio 2D∶4D in Alcohol Dependent Patients. PLoS ONE. April 2011, 6 (4): e19332. PMC 3081847可免费查阅. PMID 21547078. doi:10.1371/journal.pone.0019332. 
  66. ^ J. Kornhuber, EM Zenses, B Lenz, C Stoessel, P Bouna-Pyrrou, F Rehbein, S Kliem, T Mößle (2013): Low digit ratio 2D:4D associated with video game addiction. PLoS ONE 2013; Vol. 8, Nr. 11: e79539
  67. ^ Evardone & Alexander, Milagros; Alexander, Gerianne M. Anxiety, Sex-linked Behavior, and Digit Ratios. Arch Sex Behav. 2009, 38 (3): 442–55. PMC 2768336可免费查阅. PMID 17943431. doi:10.1007/s10508-007-9260-6. 
  68. ^ Mailhos, Alvaro; Buunk, Abraham P.; del Arca, Denise; Tutte, Verónica. Soccer players awarded one or more red cards exhibit lower 2D:4D ratios. Aggressive Behavior. 2015-12-01: n/a–n/a. ISSN 1098-2337. doi:10.1002/ab.21638 (英语). 
  69. ^ Manning JT, Taylor RP; Taylor. Second to fourth digit ratio and male ability in sport: implications for sexual selection in humans. Evolution and Human Behavior. January 2001, 22 (1): 61–69. PMID 11182575. doi:10.1016/S1090-5138(00)00063-5. 
  70. ^ Coates JM, Gurnell M, Rustichini A; Gurnell; Rustichini. Second-to-fourth digit ratio predicts success among high-frequency financial traders. Proceedings of the National Academy of Sciences of the United States of America. January 2009, 106 (2): 623–8. PMC 2626753可免费查阅. PMID 19139402. doi:10.1073/pnas.0810907106. 简明摘要时代 (杂志) (12 January 2009). 
  71. ^ Fink B, Manning JT, Neave N, Tan U; Manning; Neave; Tan. Second to fourth digit ratio and hand skill in Austrian children. Biological Psychology. November 2004, 67 (3): 375–84. PMID 15294393. doi:10.1016/j.biopsycho.2004.03.012. 
  72. ^ Titus-Ernstoff. Psychosexual Characteristics of Men and Women Exposed Prenatally to Diethylstilbestrol. CDC. 2003. 
  73. ^ Benderlioglu Z, Nelson RJ; Nelson. Digit length ratios predict reactive aggression in women, but not in men. Hormones and Behavior. December 2004, 46 (5): 558–64. PMID 15555497. doi:10.1016/j.yhbeh.2004.06.004. 
  74. ^ Liu, Jianghong; Portnoy, Jill; Raine, Adrian. Association between a marker for prenatal testosterone exposure and externalizing behavior problems in children. Development and Psychopathology. 2012-08-01, 24 (3): 771–782. ISSN 0954-5794. PMC 4247331可免费查阅. PMID 22781854. doi:10.1017/S0954579412000363. 
  75. ^ Butovskaya, Marina; Burkova, Valentina; Karelin, Dmitry; Fink, Bernhard. Digit ratio (2D:4D), aggression, and dominance in the Hadza and the Datoga of Tanzania. American Journal of Human Biology. 2015-10-01, 27 (5): 620–627. ISSN 1520-6300. PMID 25824265. doi:10.1002/ajhb.22718. 
  76. ^ Joyce, C. W.; Kelly, J. C.; Chan, J. C.; Colgan, G.; O'Briain, D.; Mc Cabe, J. P.; Curtin, W. Second to fourth digit ratio confirms aggressive tendencies in patients with boxers fractures. Injury. 2013-11-01, 44 (11): 1636–1639. ISSN 1879-0267. PMID 23972912. doi:10.1016/j.injury.2013.07.018. 
  77. ^ Beech, John R.; MacKintosh, Isla C. Do differences in sex hormones affect handwriting style? Evidence from digit ratio and sex role identity as determinants of the sex of handwriting. Personality and Individual Differences. July 2005, 39 (2): 459–68. doi:10.1016/j.paid.2005.01.024. 
  78. ^ Neave N, Laing S, Fink B, Manning JT; Laing; Fink; Manning. Second to fourth digit ratio, testosterone and perceived male dominance. 皇家学会报告. October 2003, 270 (1529): 2167–72. PMC 1691489可免费查阅. PMID 14561281. doi:10.1098/rspb.2003.2502. 
  79. ^ Burriss RP, Little AC, Nelson EC; Little; Nelson. 2D:4D and sexually dimorphic facial characteristics. Archives of Sexual Behavior. June 2007, 36 (3): 377–84. PMID 17203400. doi:10.1007/s10508-006-9136-1. 
  80. ^ Sluming, Vanessa A.; Manning, John T. Second to fourth digit ratio in elite musicians Evidence for musical ability as an honest signal of male fitness. Evolution and Human Behavior. January 2000, 21 (1): 1–9. doi:10.1016/S1090-5138(99)00026-4. 
  81. ^ Nye, John V. C.; Androuschak, Gregory; Desierto, Desirée; Jones, Garett; Yudkevich, Maria. 2D:4D Asymmetry and Gender Differences in Academic Performance. PLoS ONE. 2012, 7 (10): e46319 [2014-09-20]. PMID 23056282. doi:10.1371/journal.pone.0046319. 
  82. ^ Finger Ratio Predicts Maths Ability?. http://ibmathsresources.com/. [2014-09-20]. 
  83. ^ Austin, Elizabeth J.; Manning, John T.; McInroy, Katherine; Mathews, Elizabeth. A preliminary investigation of the associations between personality, cognitive ability and digit ratio. Personality and Individual Differences. November 2002, 33 (7): 1115–24. doi:10.1016/S0191-8869(02)00002-8. 
  84. ^ Fink et al. 2004which one?? there are two in the reference section! [查证请求]
  85. ^ Luxen, Marc F.; Buunk, Bram P. Second-to-fourth digit ratio related to Verbal and Numerical Intelligence and the Big Five. Personality and Individual Differences. October 2005, 39 (5): 959–66. doi:10.1016/j.paid.2005.03.016. 
  86. ^ Voracek, M. Who wants to believe? Associations between digit ratio (2D:4D) and paranormal and superstitious beliefs. Personality and Individual Differences. July 2009, 47 (2): 105–109. doi:10.1016/j.paid.2009.01.051. 
  87. ^ Brosnan MJ. Digit ratio as an indicator of numeracy relative to literacy in 7-year-old British schoolchildren. British Journal of Psychology. February 2008, 99 (Pt 1): 75–85. PMID 17535470. doi:10.1348/000712607X197406. 简明摘要LiveScience英语LiveScience (22 May 2007). 
  88. ^ Fink, Bernhard; Manning, John T; Neave, Nick. Second to fourth digit ratio and the ‘big five’ personality factors. Personality and Individual Differences: 495–503. doi:10.1016/j.paid.2003.09.018. 
  89. ^ Borniger, Jeremy C.; Chaudhry, Adeel; Muehlenbein, Michael P. Relationships among Musical Aptitude, Digit Ratio and Testosterone in Men and Women. PLoS ONE. 2013-03-08, 8 (3). ISSN 1932-6203. PMC 3592910可免费查阅. PMID 23520475. doi:10.1371/journal.pone.0057637. 
  90. ^ Poulin, Mary; O'Connell, Rachael L; Freeman, Louise M. Picture recall skills correlate with 2D:4D ratio in women but not men. Evolution and Human Behavior. 2004-05-01, 25 (3): 174–181. doi:10.1016/j.evolhumbehav.2004.03.004. 
  91. ^ Derval, Diana. The Right Sensory Mix: Targeting Consumer Product Development Scientifically. Springer, 2010, p. 129-130.
  92. ^ Derval, Diana. The Right Sensory Mix: Targeting Consumer Product Development Scientifically. Springer, 2010, p. 129-135.
  93. ^ Derval, Diana. The Right Sensory Mix: Targeting Consumer Product Development Scientifically. Springer, 2010, p. 62-67.
  94. ^ Derval, Diana. The Right Sensory Mix: Targeting Consumer Product Development Scientifically. Springer, 2010, p. 112-122.
  95. ^ Derval, Diana (2011). "Hormonal Quotient and tactile sensitivity: a segmentation model to understand and predict individuals' texture preferences based on prenatal exposure to hormones". Proceedings of Society for Behavioral Neuroendocrinology 15th Annual Meeting, Queretaro, Mexico, p.125.
  96. ^ 96.0 96.1 Csathó A, Osváth A, Bicsák E, Karádi K, Manning J, Kállai J; Osváth; Bicsák; Karádi; Manning; Kállai. Sex role identity related to the ratio of second to fourth digit length in women. Biological Psychology. February 2003, 62 (2): 147–56. PMID 12581689. doi:10.1016/S0301-0511(02)00127-8. 
  97. ^ 97.0 97.1 Williams TJ; Pepitone ME; Christensen SE; et al. Finger-length ratios and sexual orientation (PDF). Nature. March 2000, 404 (6777): 455–6. PMID 10761903. doi:10.1038/35006555. 
  98. ^ 98.0 98.1 Tortorice JL. Written on the body: butch vs. femme英语butch and femme lesbian gender identity and biological correlates of low digit ratio. Rutgers University. 2002. OCLC 80234273. 
  99. ^ 99.0 99.1 99.2 McFadden D, Shubel E; Shubel. Relative lengths of fingers and toes in human males and females. Hormones and Behavior. December 2002, 42 (4): 492–500. PMID 12488115. doi:10.1006/hbeh.2002.1833. 
  100. ^ 100.0 100.1 Hall LS, Love CT; Love. Finger-length ratios in female monozygotic twins discordant for sexual orientation. Archives of Sexual Behavior. February 2003, 32 (1): 23–8. PMID 12597269. doi:10.1023/A:1021837211630. 
  101. ^ 101.0 101.1 Rahman Q, Wilson GD; Wilson. Sexual orientation and the 2nd to 4th finger length ratio: evidence for organising effects of sex hormones or developmental instability?. Psychoneuroendocrinology. April 2003, 28 (3): 288–303. PMID 12573297. doi:10.1016/S0306-4530(02)00022-7. 
  102. ^ Putz, David A.; Gaulin, Steven J. C.; Sporter, Robert J.; McBurney, Donald H. Sex hormones and finger length: What does 2D:4D indicate? (PDF). Evolution and Human Behavior. May 2004, 25 (3): 182–99. doi:10.1016/j.evolhumbehav.2004.03.005. 
  103. ^ 103.0 103.1 Rahman Q. Fluctuating asymmetry, second to fourth finger length ratios and human sexual orientation. Psychoneuroendocrinology. May 2005, 30 (4): 382–91. PMID 15694118. doi:10.1016/j.psyneuen.2004.10.006. 
  104. ^ 104.0 104.1 Kraemer B, Noll T, Delsignore A, Milos G, Schnyder U, Hepp U; Noll; Delsignore; Milos; Schnyder; Hepp. Finger length ratio (2D:4D) and dimensions of sexual orientation. Neuropsychobiology. 2006, 53 (4): 210–4. PMID 16874008. doi:10.1159/000094730. 
  105. ^ 105.0 105.1 Wallien MS, Zucker KJ, Steensma TD, Cohen-Kettenis PT; Zucker; Steensma; Cohen-Kettenis. 2D:4D finger-length ratios in children and adults with gender identity disorder. Hormones and Behavior. August 2008, 54 (3): 450–4. PMID 18585715. doi:10.1016/j.yhbeh.2008.05.002. 
  106. ^ 106.0 106.1 Grimbos T, Dawood K, Burriss RP, Zucker KJ, Puts DA; Dawood; Burriss; Zucker; Puts. Sexual orientation and the second to fourth finger length ratio: a meta-analysis in men and women. Behav Neurosci. 2010, 124 (2): 278–287. PMID 20364887. doi:10.1037/a0018764. 
  107. ^ 107.0 107.1 Hirashi K, Sasaki S, Shikishima C, Ando J; Sasaki; Shikishima; Ando. The second to fourth digit ratio (2D:4D) in a Japanese twin sample: heritability, prenatal hormone transfer, and association with sexual orientation. Arch Sex Behav. Jun 2012, 41 (3): 711–24. PMID 22270254. doi:10.1007/s10508-011-9889-z. 
  108. ^ 108.0 108.1 S.J. Robinson, J.T. Manning; Manning. The ratio of 2nd to 4th digit length and male homosexuality. Evolution and Human Behavior. 2000, 21 (5): 333–345. PMID 11053694. doi:10.1016/S1090-5138(00)00052-0. 
  109. ^ McIntyre MH. Digit ratios, childhood gender role behavior, and erotic role preferences of gay men. Archives of Sexual Behavior. December 2003, 32 (6): 495–6. PMID 14627046. doi:10.1023/A:1026054625638. 
  110. ^ Brown WM, Finn CJ, Cooke BM, Breedlove SM; Finn; Cooke; Breedlove. Differences in finger length ratios between self-identified 'butch' and 'femme' lesbians (PDF). Archives of Sexual Behavior. February 2002, 31 (1): 123–7. PMID 11910785. doi:10.1023/A:1014091420590. 
  111. ^ Hiraishi K, Sasaki S, Shikishima C, Ando J.; Sasaki; Shikishima; Ando. The second to fourth digit ratio (2D:4D) in a Japanese twin sample: heritability, prenatal hormone transfer, and association with sexual orientation. Archives of Sexual Behavior. 2012, 41 (3): 711–24. PMID 22270254. doi:10.1007/s10508-011-9889-z. 
  112. ^ Churchchill AJG, Manning JT, Peters M; Manning; Reimers. The effects of sex, ethnicity, and sexual orientation on self-measured digit ratio (2D:4D). Archives of Sexual Behavior. 2007, 36 (2): 251–260. PMID 17394056. doi:10.1007/s10508-006-9166-8. 
  113. ^ Yule MA, Brotto LA, Gorzalka BB. Biological markers of asexuality: Handedness, birth order, and finger length ratios in self-identified asexual men and women.. Arch Sex Behav. 2014 [2014]. 
  114. ^ M.V. Voracek, J.T. Manning & I. Ponocny; Manning; Ponocny. Digit ratio (2D:4D) in homosexual and heterosexual men from Austria. Archives of Sexual Behaviour. 2005, 34 (3): 335–340. PMID 15971016. doi:10.1007/s10508-005-3122-x. 
  115. ^ Teresa Grimbos; Kenneth Zucker英语Kenneth Zucker; Khytam Dawood; Robert P. Burriss. Sexual Orientation and the Second to Fourth Finger Length Ratio: A Meta-Analysis in Men and Women (PDF). Behavioral Neuroscience. 2010, 124 (2): 278 –287. PMID 20364887. doi:10.1037/a0018764. 
  116. ^ Schneider HJ, Pickel J, Stalla GK; Pickel; Stalla. Typical female 2nd-4th finger length (2D:4D) ratios in male-to-female transsexuals-possible implications for prenatal androgen exposure. Psychoneuroendocrinology. February 2006, 31 (2): 265–9. PMID 16140461. doi:10.1016/j.psyneuen.2005.07.005. 
  117. ^ Ronalds, G; Phillips, DI; Godfrey, KM; Manning, JT. The ratio of second to fourth digit lengths: A marker of impaired fetal growth?. Early human development. 2002, 68 (1): 21–6. PMID 12191526. doi:10.1016/s0378-3782(02)00009-9. 
  118. ^ Fink B; Grammer K; Mitteroecker P; et al. Second to fourth digit ratio and face shape. 皇家学会报告. October 2005, 272 (1576): 1995–2001. PMC 1559906可免费查阅. PMID 16191608. doi:10.1098/rspb.2005.3179. 
  119. ^ Fink, Bernhard; Manning, John T.; Neave, Nick; Grammer, Karl. Second to fourth digit ratio and facial asymmetry. Evolution and Human Behavior. March 2004, 25 (2): 125–32. doi:10.1016/S1090-5138(03)00084-9. 
  120. ^ Snow, Dean R. Sexual dimorphism in Upper Palaeolithic hand stencils. Antiquity. 2006, 80 (308): 390–404. 
  121. ^ Chazine, Jean-Michel; Noury, Arnaud. Sexual Determination of Hand Stencils at the Masri II Cave. Inora Newsletter. 2006, 44: 21–6. 
  122. ^ Nelson, Emma C.; Manning, John T.; Sinclair, Anthony G. M. Using the length of the 2nd to 4th digit ratio (2D:4D) to sex cave art hand stencils: factors to consider (PDF). Before Farming. 2006, 1 (6): 1–7. 
  123. ^ Nelson, Emma. Investigating relationships between the second-to-fourth digit ratio (2D:4D), social and bonding behaviours in non-human anthropoids. [29 October 2009]. (原始内容存档于8 November 2011). [自述来源]
  124. ^ Talarovičová A, Kršková L, Blažeková J; Krsková; Blazeková. Testosterone enhancement during pregnancy influences the 2D:4D ratio and open field motor activity of rat siblings in adulthood. Hormones and Behavior. January 2009, 55 (1): 235–9. PMID 19022257. doi:10.1016/j.yhbeh.2008.10.010. 
  125. ^ Yan RH, Malisch JL, Hannon RM, Hurd PL, Garland T; Malisch; Hannon; Hurd; Garland Jr. Svensson, Erik I. , 编. Selective Breeding for a Behavioral Trait Changes Digit Ratio. PLoS ONE. 2008, 3 (9): e3216. PMC 2528935可免费查阅. PMID 18797502. doi:10.1371/journal.pone.0003216. 

外部链接