ASSOCIATIONS AMONG RATIO OF DIGIT LENGTHS (2D: 4D), HAND PREFERENCES, NONVERBAL INTELLIGENCE, VISUAL, AUDITORY AND VERBAL ABILITY, MOTOR SKILL AND CEREBRAL LATERALIZATION IN HEALTHY PERSONS

Abstract

OBJECTIVE: In this study, the associations among the parameters of hand, foot and eye preferences, ratio of digit lengths (2D: 4D), nonverbal intelligence (IQ), hand motor skill in man and women were aimed to investigate.

METHODS: . A total of 439 (245 girls and 194 boys) volunteer participants were included fort his study. The parameters were determined as folllows: Hand preference using ‘Edinburg Hand Preference Questionnaire’, IQ point using ‘Cattell’s Culture Free Intelligence Test’ and motor skill using ‘Nail Movement Test’, eye and foot lateralization were determined. Respective finger length from anatomic boundaries was measured using digital compass caliper and the ratios of (2D: 4D) were calculated.

RESULTS: Right-handed preference was found to be higher in women than men, but it was not meaningful (p=0,807). It’s found that, 63.7% of women right eye, 75.9% of women right foot and 61.9% men right eye, 58.2% of men right foot were dominance. Considering the sex, It’s not found meaningful difference between right and left hand preference ratios (2D: 4D). In girl’s, between right and left hand preference ratios and motor skill, lateralization, It’s not found meaningful relation. There was a positive correlation between right hand (2D: 4D) ratios and IQ test results (r =0.146). Nail motion test between girls and boys, were found to be significantly different (p<0.005).

CONCLUSION: In conclusion, it was determined that right hand preference in girl’s and left hand preference in boy’s were higher. It is also determined that, right hand people has dominance at right eye and foot too. Altogether, in light of this study it was concluded that the motor skills were higher in men who have more lateralization (towards right).

Keywords

• Digit length ratio
• nonverbal intelligence
• motor skill
• hand

SAĞLIKLI BİREYLERDE PARMAK UZUNLUK ORANLARININ (2D: 4D); EL TERCİHİ, NONVERBAL ZEKA, GÖRSEL, İŞİTSEL VE VERBAL YETENEKLER, MOTOR BECERİ VE SEREBRAL LATERALİZASYON İLE İLİŞKİSİ

Abstract

AMAÇ: Çalışmada, bayanlar ve erkeklerde el, ayak göz tercihleri, parmak uzunluk oranları, nonverbal zeka (IQ), el motor becerisi ve bu parametreler arası ilişkilerin araştırılması amaçlanmıştır. YÖNTEMLER: Toplam 439 (245 kız ve 194 erkek) gönüllü katılımcıya, ‘Edinburg El Tercihi Anketi’, ‘Cattell’s Culture Free Intelligence Test’ ve ‘Çivi Hareket Testi’ uygulandı. Göz ve ayak lateralizasyonu tespit edildi. Her el için ayrı ayrı parmak uzunlukları anatomik sınırlardan dijital kumpasla ölçüldü ve parmak oranları hesaplandı.

BULGULAR: Sağlak kız öğrencilerin sayısı erkeklerden fazla idi. Ancak istatistiksel olarak anlamlı bir fark saptanmadı (p=0,807). Kız öğrencilerin %63.7’sinin sağ gözü, %75.9’nun sağ ayağı dominant iken, erkeklerde sağ gözü kullanma oranı %61.9, sağ ayak dominantlığı %58.2 bulundu. Cinsiyete göre sağ ve sol el için parmak oranları arasındaki fark istatistiksel açıdan önemli değildi. Kız öğrencilerin sağ ve sol el oranları, motor beceri ve lateralizasyon arasında da anlamlı bir ilişki yoktu. Fakat sağ el parmak oranları ve IQ testi ilişkili idi (r =0.146). Çivi hareket testinin, kızlarla erkekler arasında, anlamlı farklı olduğu gözlendi (p<0.005). SONUÇ: Sonuç olarak, kızlarda sağlaklığın, erkeklerde ise solaklığın daha yaygın olduğu, azda olsa zayıf bir ilişki gösteren sağlakların sağ ayak ve gözde de dominantlık gösterdiği, erkeklerde sağlaklık arttıkça el becerisinin arttığı saptandı.

Keywords

• Parmak uzunluk oranı
• nonverbal zeka
• motor beceri
• el
• ayak

References

1. 1. Broca P. Localisation des fonctions ce´re´brales. Sie`ge dulangage articule. Bulletins de la. Société d'Anthropologie. 1863;4:200-204.
2. 2. Saenger VM, Barrios FA, Martínez-Gudi˜no ML, et al. Hemispheric asymmetries of functional connectivity and grey matter volume in the default mode network. Neuropsychologia. 2012;50:1308-1315.
3. 3. Powell JL, Parkes L, Kemp GJ, et al. The effect of sex and handedness on whıte matter anısotropy: a dıffusıon tensor magnetıc resonance ımagıng study. Neuroscience. 2012;207:227-242.
4. 4. McManus IC, Bryden MP. Geschwind's theory of cerebral lateralization: Developing a formal, causal model. Psychological Bulletin. 1991;110(2):237-253.
5. 5. Corballis MC, Badzakova-Trajkov G, Ha¨berling IS. Right hand, left brain: genetic and evolutionary bases of cerebral asymmetries for language and manual action. WIREs Cognitive Science. 2012;3:1-17.
6. 6. Galaburda AM, Eıdelberg D. Symmetry and asymmetry in the human posterior thalamus. II. Thalamic lesions in a case of evelopmental dyslexia. Archives of Neurology. 1982;39:333-336.
7. 7. Dane Ş, Balcı N. Handedness, eyedness and nasal cycle in children with autism. Internatıonal Journal of Neuroscıence. 2007;25:223-226.
8. 8. Prevıc FH. A general theory concerning the prenatal origins of cerebral lateralization in humans. Psychological Review. 1991;98:299-334.

9. 9. Ronalds G, Phillips DIW, Godfrey KM, et al. The ratio of second to fourth digit lengths:a marker of impaired fetal growth. Early Human Development. 2002;68:21-26.
10. 10. Manning J.T, Taylor R.P. Second to fourth digit ratio and male ability in sport: implications for sexual selection in humans. Evolution and Human Behavior. 2001;22:61-69.
11. 11. Tester N, Campbell A. Sporting achievement: what is the contribution of digit ratio? Journal of Personality. 2007;75:663-677.
12. 12. Floyd G, McGrew S, Barry A, et al.General and Specific Effects on Cattell–Horn–Carroll Broad Ability Composites: Analysis of the Woodcock– Johnson III Normative Update Cattell–Horn–Carroll Factor Clusters Across Development. School Psychology Review. 2009;38:249-265.
13. 13. Tan U. The distribution of hand preference in normal men and women. Internatıonal Journal of Neuroscıence. 1988;41:35-65.
14. 14. Tan U. Relationships between hand skill and the excitability of motor neurons innervating the postural soleus muscle in human subjects. Internatıonal Journal of Neuroscıence. 1985;26:289-300.
15. 15. Badzakova-Trajkov G, Häberling IS, Roberts RP, et al. Cerebral asymmetries: Complementary and independent processes. PloS One. 2010;5(3):9682.
16. 16. McManus IC. Handedness, laguage dominance and aphasia: A genetic model. Psychological Medicine Monograph Supplement. 1985;8:1-40.
17. 17. Rhoshel K, Lenroot AB, Jay N, et al. Sex differences in the adolescent brain. Brain and Cognition. 2010;72:46-55.
18. 18. Moffat SD, Hampson E. Salivary testosterone levels in left-and-right handed adults. Neuropsychologia. 1996;34:225-233.
19. 19. Seizeur R, Magro E, Prima S, et al. Corticospinal tract asymmetry and handedness in right- and left-handers by diffusion tensor tractography. Surgical and Radiologic Anatomy. 2013 (Baskıda).
20. 20. Bourassa DC, McManus IC, Bryden MP. Handedness and eye-dominance: a meta-analysis of their relationship. Laterality. 1996;1:5-34.
21. 21. Annett M, Turner A. Laterality and the growth of intellectual abilities. British Journal of Educational Psychology. 1974;44:37-46.
22. 22. Dane S, Gumustekin K. Handedness in deaf and normal children. Internatıonal Journal of Neuroscıence. 2002;112:995-998.
23. 23. Walls GL. A theory of ocular dominance. Archives of Ophthalmology. 1951;45:387-412.
24. 24. Powell HWR, Parker GJM, Alexander DC, et al. Hemispheric asymmetries in language-related pathways: a combined functional MRI and tractography study. Neuroimage. 2006;32(1):388-399.
25. 25. Hagmann P, Cammoun L, Martuzzi R, et al. Hand preference and sex shape the architecture of language networks. Human Brain Mapping. 2006;27(10):828-835.
26. 26. Manning JT, Stewart A, Bundred PE, et al. Sex and ethnic differences in 2nd to 4th digit ratio of children. Early Human Development. 2004;80:161-168.
27. 27. Robinson SJ, Manning JT. Ratio of 2nd to 4th digit length and male homosexuality. Evolution and Human Behavior. 2000;21(5):333-345.
28. 28. Galis F, Ten Broek CMA, Van Dongen S, et al. Sexual Dimorphism in the Prenatal Digit Ratio (2D:4D). Archives of Sexual Behavior. 2010;39(1):57-62.
29. 29. Tan Ü, Akgün A, Telatar M. Relationships among nonverbal intelligence, hand speed, and serum testosterone level in left-handed male subjects. Internatıonal Journal of Neuroscıence. 1993b;71:21-28.
30. 30. Hooven CK, Chabris CF, Ellison PT, et al. The relationship of male testosterone to components of mental rotation. Neuropsychologia. 2004;42(6):782-790.
31. 31. Spritzer MD, Daviau ED, Coneeny MK, et al. Effects of testosterone on spatial learning and memory in adult male rats. Hormone and Behavior. 2011;59(4):484-496.