Variation in Human Sizeand Body Proportions

BPK303

Somatotype

William Sheldon

Photoscopic ratings based on listed criteriaEndomorphy – Mesomorphy – Ectomorphy

Ratings 1 to 73-4-3, 1-1-7, 2-6-2

Heath-Carter Anthropometric Somatotype

Endomorphy (the first component) refers to relative fatness in physique. Mesomorphy (the second component) refers to relative development of the musculo-skeletal system. Ectomorphy (the third component) refers to relative linearity of physique.Ratings 0.5 to >7

Lindsay Carter & Barbara Heath-Roll

circa 1983

Extreme Ectomorphy

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Dinka tribe of the Sudan are the most naturally ectomorphic ethnic group reported.

Manute Bol former NBA player with his then team mate Spud Webb

Comparison of Mean Somatotypes of Female Ethnic samples

Young Manus

Females

KIN-ScaleProportionality Profile

KIN-Scale data composed of data from Kin 303 students 2004-2011.

Means and SEMs of z-values for KIN-Scale Males (n=230) and Females (n=336)

Visual test of significance allows for a lot of information to be portrayed in one figure

Sexual Dimorphism in KIN-Scale subjects

No difference in proportional weight

Male-Female difference greatest in: Triceps, Biceps, Front Thigh and Medial Calf Skinfolds Secondary sexual adiposity

Sexual Dimorphism in KIN-Scale subjects

Representative Measures

Muscle Mass Muscle X-sectional Area Skinfold-Adjusted Arm Girth – Muscularity Indicator

G

Ga = G - (3.14xS)

S = Skinfold ThicknessG = GirthGa = Skinfold adjusted Girth

Ga

SG

Girth adjusted for Skinfold at that site

Girth Skinfold

s.a. Arm girth Relaxed Arm Girth Triceps

s.a. Chest girth Chest Subscapular

s.a. Thigh girth Thigh Front Thigh

s.a. Calf girth Calf Medial Calf

s.a. Forearm girth Maximum Forearm Forearm

s.a. Girth (cm) = Girth (cm) - (Π x Skinfold (mm) / 10)

Sexual Dimorphism in KIN-Scale subjects

s.a. Girths are Muscularity indicators

Greatest differences between the sexes in the upper body

Greatest potential for hypertrophy in the upper body

Muscularity profile is very sensitive to the specific activity of the individual

Sexual Dimorphism in KIN-Scale subjects

Proportionally larger sitting height in females

Males tend to have proportionally longer limbs.

Biggest difference in distal segments

Sexual Dimorphism in KIN-Scale subjects

Humerus to Femur Width differences reflects muscularity differences

Males have broader and deeper chests proportionally.

Classic hip-shoulder dimorphism:

Males proportionally wider shoulders

Females have proportionally wider hips

Shoulder-Hip Dimorphism

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  Sex N MeanStd.

Deviation

Biacromial/Biiliocristal Breadth Male 69 1.44 0.12

  Female 115 1.31 0.12

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2D:4D Ratio(2nd digit length to 4th digit length ratio)

Sex N Mean Std. Deviation

Male 136 0.947 0.029

Female 137 0.965 0.026

2D 4D

a Allison A. Bailey, Peter L. Hurda, Department of Psychology, University of Alberta. 2004

2D:4D Ratio

Ratio determined in utero 2D:4D is negatively correlated with prenatal testosterone and

positively correlated with prenatal estrogen

Larger ratio in females Married women had higher 2D:4D ratios than unmarried women Significant negative associations were found between 2D:4D in

men and reproductive success and significant positive relationships between 2D:4D in women and reproductive success

Found to be related to: Aggression Competitive success Sexual orientation

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Histogram of Both Sexes Combined

Sex N Mean S.D.

Male 76 0.975 0.037 Female 66 0.994 0.043

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Racial/Ethnic and Individual Differences

Chinese South Asian European