8 Sheldon and Parnell Classification of Somatotype

Dr. Mary Grace Tungdim

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Contents:

 

1.0 Introduction

1.1 History and Earlier Classification of Somatotypes

2.0 William Sheldon and Somatotypes

2.1 Sheldon’s classification of Somatotype

3. Richard Parnell and Somatotypes

4. Further works after Sheldon and Parnell

5. Factors which affect Somatotype

6. Issues with Somatotype Studies in Criminology

 

Learning Outcomes

  1. The student will come to know about the history and earlier classification of somatotypes and the development of Sheldon’s classification.
  2.  The learner will also be able to comprehend the M.4 Deviation of Richard Parnell, factors which affect somatotyping and further works after Sheldon and Parnell.

1.0 Introduction

 

Somatotypes refer to the outer-most, morphological forms of human bodies whose classification is based on appearance characteristics and change according to physical constitution, environment, disease, nutrition and exercise. Somatotypical studies have contributed to our understanding of diversity of human builds and been applied to specific diseases, osteoporosis, relations between musculoskeletal system and ageing, exercise programs for individual athletes, and potentials of athletes. In fact, Sheldon developed the idea of somatotype in his search to find the relationship between human physique and behavior. Somatotypes are affected by environmental factors such as occupation, nutrition, housing, medical support, and lack of primary health medicine. They are important in our daily life for their useful application in industries of electronics and clothes as well as anthropology, bio-engineering, medicine, and sports. Especially, in the area of physical therapy, somatotype studies related to thermal and integumentary physical therapy, musculoskeletal system exercise treatment, obesity control physical therapy, and sports physical therapy were diligently pursued.

 

Experts of medicine, philosophy and psychology found that human somatotypes were related to personality or physical characteristics and classified somatotypes into various forms. This study explored the changes and types of somatotyping methods from Before Christ (BC) to present day and identified the status of studies of somatotypes in the area of physical therapy. This study covered the methods applied in various subjects with a focus on those provided in books and papers of Heath BH. and Carter JEL. Based on the results, there are officially twelve assessment methods. Currently, the method of Heath & Carter is most widely applied. Somatotypes are studied in many areas. It is actively explored in the area of pain physical therapy, thermotherapy and integumentary physical therapy. Also, the soft tissue physical therapy area seeks interdisciplinary studies.

 

1.1     History and Earlier Classification of Somatotypes

Somatotyping is the most recent development in the twenty five century history of morphological taxonomy and constitutional investigation. The foundations of the classification of human physique started in the 5th century BC, Hippocrates, a Greek doctor divided somatotypes into habitus phthisicus and habitus apoplecticus. The former refers to long and thin body builds which are vulnerable to tuberculosis and the latter is short and fat body builds which are more exposed to blood vessel diseases and strokes. Celsus, an editor of the Roman Medical Encyclopedia in the 1st century AD wrote that it was necessary to learn about the nature of constitution in order to understand why a certain person was thin while others were not. Galen, a Greek doctor in the 2nd century AD, maintained the theory of four types of humours and said we needed to know patients’ humour constitution for diagnosis and treatment of diseases. In the 4th century BC, Aristotle said specific bodies had specific characteristics. In the early 11th century, an Arabic doctor and philosopher, Avicenna recommended the study of temperament as it is related to character. The typological system based on Hippocrates’s pattern was famous in France between late 18th century and early 19th century. In 1797 and 1828, Halle and Rostan, respectively, described the three physical constitutions covering type digestif, type musculaire, and type cerebrale.

 

Johann Sigismund Elsholtz, at the University of Padua in the seventeenth century first used anthropometry in the studies of morphology. Later in about 1880, Huter divided them into cerebral(ectomorphy is prevalent), muscular(mesomorphy is prevalent) and digestive (endomorphy is prevalent) types. Kretschmer was a German psychologist who wrote about physical and psychological forms in his book published in 1921, ‘Körperbau und Charakter (Physique and character)’. He divided somatotype into leptosome habitus, athletic habitus, and pyknic habitus. His types are similar to di Giovanni’s grouping in which the gradual changes from psychose to normality are recognized. Leptosome habitus was a type where height is long but bone and muscle development is poor, corresponding to introvert people. Athletic habitus stands between pyknic habitus and leptosome, referring to body types of narrow shoulders and large muscles and bones. Pyknic habitus is small in height. They have narrow shoulders and thick bodies. Obese type is merry, sociable, and extrovert people.

Dating back to the times of Cesare Lombroso, there have been numerous attempts to study about physique and the different methods of measuring physique. Some of these measurements have been simple while others have been complex. For instance, Earnest Hooton separated height and weight into a 3 × 3 matrix, or nine subgroups, to see if there was a relationship between physique and crime; height was identified as short, medium, and tall, and weight was identified as slender, medium, and heavy. This example outlines a simple method for the determination of physique of a person.

A more complex method of determining physique can be found in the work of Ernst Kretschmer. By the year 1800, a host of physique studies were completed in Europe and it was Kretschmer who completed one of the paramount studies of physique. Originally published in 1931, Kretschmer’s study of ‘Physique and Character’, comprised of 400 patients of all ages and different occupations in a hospital. This study was conducted in an effort to link physique and character. The key contribution of Kretschmer to physical determination was that he established the three types of physique viz,: the asthenic, athletic, and pyknic forms. A person could have characteristics from each of Kretschmer’s types, building for a blended physical type. According to Kretschmer, the extreme asthenic type is characterized as weak and frail and a person with this type of physique has a deficiency in thickness combined with an average unlessened length. The extreme athletic type of physique is recognized by the strong development of the skeleton, the musculature and also the skin. The extreme pyknic type of physique is characterized by the pronounced peripheral development of the body cavities, and a predisposition to distribution of fat around the trunk region, with a more refined structure of the motor apparatus (Maddan 2010).

 

2.0 William Sheldon and Somatotypes

William H. Sheldon graduated from the University of Chicago with a Ph.D. in Psychology in 1926 and with an M.D. in 1933. He held positions as a professor at the University of Oregon Medical School, where he was also the director of the constitution clinic, and the director of the Biological Humanics Foundation in Cambridge, Massachusetts. Sheldon introduced the term and concept of somatotype in his book ‘The Varieties of Human Physique’ published in the year 1940. As the three basic elements determining body builds, he focused on intestines generated from embryological endomorphy, bones and muscles developed from mesomorphy, and skin, sensual organs, and nervous development from ectomorphy and combined them to classify into a few categories. Sheldon’s endomorphy, mesomorphy, and ectomorphy are similar to Kretschmer’s pyknic habitus, athletic habitus, and leptosome habitus, respectively.

 

2.1 Sheldon’s classification of Somatotype

Sheldon recognized that every individual instead of being of a particular type was a mixture of all three basic components of physique. They are: endomorphy, mesomorphy and ectomorphy.

Endomorphy: According to Sheldon, Endomorphy type means virtual preponderance of soft roundedness all over the various regions of the human body. When endomorphy is dominant the digestive viscera are massive and tend to relatively dominate the bodily economy. The digestive viscera are derived principally from the endodermal embryonic layer and as a result the people with thick fat layers have bone structures developed from endomorphy. This type of people are round and fat in shape.

 

Mesomorphy: Mesomorphy means the virtual preponderance of the body muscle, bone, and connective tissue. The mesomorphic physique is normally heavy, hard and rectangular in outline. In mesomorphy bone and muscle are predominant and the skin is made thick by heavy underlying connective tissue. The entire bodily economy is relatively dominated by tissues derived from the mesodermal embryonic layer. These types of people are muscular and robust with bone structures developed from mesomorphy.

Ectomorphy: Ectomorphy means relative predominance of linearity and fragility. In proportion to mass, the ectomorph has the greatest surface area and hence relatively the greatest sensory exposure to the outside world and the largest brain and central nervous system. In a sense, therefore, his bodily economy is relatively dominated by tissues derived from ectodermal embryonic layer. The ectomorphic type of people are thin and have bone structures developed from ectomorphy from their births.

Sheldon stated that the somatotype is a trajectory along which an individual under average nutritional conditions and absence of major illness is destined to travel. He used the word ‘morphophenotype’ to refer to the present physique and ‘morphogenotype’ to the genetically determined physique. Sheldon further said that somatotype does not change throughout a person’s life.

In ‘The varieties of Human Physique’, 1940 Sheldon wrote that ‘the problem of somatotyping is to discover “objective” anthropometric correlates for the “subjective” discriminable aspects. Sheldon chose an arbitrary scale that permitted no rating more than 7 or less than 1 in any one component. Sheldon used somatotype photographs, the record of present height and weight, a table of somatotypes distributed by the cube root of weight and anthroscopy.

Sheldon (1940) summarized his photoscopic method which he called anthroposcopic somatotype method as follows:

  1.  Calculation of /weight ratio(HWR)
  2. Calculation of ratios of 17 transverse measurements (taken from photographic negatives) to stature. The transverse measurements, selected from factor analysis of 32 measurements were: four on the head and neck, three on the thoracic trunk, three on the arms, three on the abdominal trunk and four on the legs.
  3.  Inspection of the somatotype photograph, referring to a table of known somatotypes distributed against the criterion of HWR, comparing the photograph with a file of correctly somatotyped photographs and recording the estimated somatotype.
  4. Comparison of the 17 transverse measurement ratios with a range of scores for each ratio, to give a final score.

However, Sheldon was persistently criticized because of the following:

  1.  The somatotypes changes
  2.  Somatotype is not objective
  3.  There are two, not three, primary components, for endomorphy and ectomorphy are essentially the inverse of each other, and
  4.  Somatotyping omits the factor of size.

In order to meet the above criticisms and negative reactions provided by his somatotype system as presented in The Varieties of Human Physique and in the Atlas of Men, Sheldon (1961, 1965; Sheldon et al., 1969) described a new Trunk Index method.

The Trunk Index somatotype is calculated from the following data:

 

1.    The trunk index obtained from planimetry of standard somatotype photographs.

2.   Maximal and minimal weight and stature reported by the subject.

3.   Table of HWRs and trunk indices.

4.   A table of somatotypes plotted against maximal stature.

5.   Basic tables for somatotyping which combine the Trunk Index, maximal stature and the SPI(somatotyping ponderal index, i.e. the lowest ponderal index on record). The tables are corrected for age and are read differently for men and women. Nothing is said about using them for children, or for subjects shorter than 137 cm(males) or 127 cm (females).

Those classified based on this system will have three-digit body shape numbers. The first to third digits related to endomorphy to ectomorphy order and each digit has a scale ranging from one to seven. The sum of the three components may range from 7 to 15. Higher number relates to more definite classification. For example, extreme endomorphy type is displayed as 711. The first digit, 7 is the degree of endomorphy while the second and third digits, 1 and 1, respectively refer to the degrees of mesomorphy and ectomorphy. If someone pertains to the extreme endomorphy type and shows little mesomorphy but medium level of ectomorphy, this person will be 714. Therefore, 171 and 117 will stand for extreme mesomorphy and ectomorphy, respectively. While the classification numbers are of mutually exclusive correlations, if one class provides a higher mark, there will be no higher marks in other classes. Actually, the extreme forms such as 711, 171, and 117 are rare or non-existent and normal builds will be near 444.

Drawing directly from the work of Kretschmer, Sheldon delineated the study of physique and the dimension of somatotypes in his book ‘The Varieties of Human Physique’ in the year 1940. Sheldon’s theory was founded on the hypothesis that it is possible to determine physical distinctions among human beings. He also focused on three extreme physical types, adapted from embryology, which corresponded approximately to Kretschmer’s physical typology: endomorphs (pycknic), mesomorphs (athletic), and ectomorphs (asthenic). These three types were selected because they illustrated the most extreme cases of physique. Sheldon and colleagues further defined endomorphy as the ‘relative predominance of soft roundness throughout the various regions of the body’ (Sheldon, 1940). Mesomorphy is referred to the ‘relative predominance of muscle, bone, and connective tissue’. Ectomorphy is referred to the ‘relative predominance of linearity and fragility’; Sheldon noted that this form had the largest brain and central nervous system (Maddan et al. 2008). Sheldon examined 400 male undergraduate students at the University of Chicago to refine his measurement. In an effort to standardize his method, Sheldon took photographs of naked subjects from three angles: front view, side view, and back view; where the subject stood on a pedestal a certain distance away from the camera. From the 400 subjects, 4,000 photographs were collected and examined. A total of 17 measurements (dependent on the height to convert into ratio form) were taken from a body of these photographs. From this, a three-number scale was derived to conclude a person’s somatotype. The first number in the score reflects the amount of endomorphy in an individual, the second number represents the amount of mesomorphy in an individual, and the third number represents the amount of ectomorphy present in an individual. Thus, an extreme endomorph would receive a score of 7–1–1, an extreme mesomorph would receive a score of 1–7–1, and an extreme ectomorph would receive a score of 1–1–7 (Maddan 2010).

 

In 1949, for the first time Sheldon tested his method of somatotyping in studying crime. He followed the lives of a sample of 200 young men from a social service agency called the Hayden Goodwill Inn. The sample consisted of youth with antisocial personalities as well as delinquent histories which gave Sheldon’s study a comparison group of noncriminals on which to base his results. Although he examined many different sociological variables as well as biological variables, the main finding among the criminal sample, in terms of somatotypes, was that mesomorphy was the most common somatotype. Therefore, Sheldon concluded that delinquents were more inclined to being mesomorphically built. With the exception of a 30-year follow-up study, this would also mark the last time that Sheldon’s method of somatotyping would be used in the study of the link between physique and crime. In the 30-year follow up of Sheldon’s research, Hartl et al. (1982) reexamined the 200 men whose biographies were presented by Sheldon in 1949. One of their major finding was that future adult criminals differed from noncriminal subjects in the sample in terms of mesomorphy.

  1. Richard Parnell and Somatotypes

It was Richard Parnell’s work in 1958 which inevitably eclipsed Sheldon’s somatotyping approach. R.W. Parnell (1954), a British physician, described a method known as Parnell’s M.4 deviation chart method to objectively somatotype human subjects by physical anthropometry. Therefore, Parnell’s method of somatotyping was considered to be more objective as compared to Sheldon’s method. Parnell (1958) remarked that the phenotype is the body as it appears at a particular point in time. Because of this, Parnell indicated that his method for somatotyping was not a good variable for prediction purposes (Maddan et al. 2008). Parnell labeled his physical types on the chart as Fat, Muscularity, and Linearity, which correspond to the classification of Sheldon’s viz.; endomorph, mesomorph, and ectomorph respectively.

 

Parnell developed the scoring method to use anthropometric measurement and recorded the results in M.4 deviation charts to use them along with the pictures. Parnell’s method of somatotyping requires height, weight and measures of muscle girth (biceps and calf), femoral and humeral epicondylar diameters and skinfold thickness in three areas viz.; triceps, subscapular and suprailiac.

 

The M.4 deviation chart included tables to obtain anthropometric somatotypes (Fig. 4). Assessments of Fat, Muscularity and Linearity were obtained to the nearest quarter point on a seven scale, giving phenotypes similar to Sheldon’s somatotypes. Parnell replaced Sheldon’ component name with fat, muscular (muscularity), and thin type (linearity), abbreviated as F, M and L, respectively. The fat (endomorphy type) type decision is based on skinfold measurement while the muscular type (mesomorphy type) works based on height, bone diameter, and limb thickness. The thin type (ectomorphy type) works based on HWRs. As shown in the M.4 Deviation Charts for Adults, the three element scales were collected from various age brackets (Parnell, 1954; Parnell, 1958). This method of somatotyping emphasized the phenotype, not the somatotype.

Fig. 4. The Parnell M.4 adult Deviation chart with the values for the Harpenden chart for determining the somatotype. This skinfold caliper inserted for the chart is based on Parnell’s (1958, p.21) determination of the endomorphy estimate

Parnell’s effort was to describe a short physical anthropometric method for obtaining with the following purposes (Singh & Mehta, 2009):

  1. To provide objective guidance on the dominance of somatotype components in a healthy person.
  2. To estimate the Sheldonian somatotype objectively and as accurately at least as the agreement achieved between experts in photoscopic somatotyping.
  3. To make an estimate of women’s somatotype possible although in the absence of a published reference somatotype data estimate cannot be compared.
  4. To reduce on cost, labour and time while doing somatotypes.

4.Further works after Sheldon and Parnell

 

Stimulated by the works of Sheldon and Parnell on somatotyping, Eleanor Glueck with the help of Sheldon conducted an analysis on the relationship between physique and crime. The Gluecks (1951) compared the physiques between a sample of delinquents and a sample of nondelinquents. The Gluecks took the aid of a physical anthropologist to measure the somatotypes of their subjects. It was Parnell’s method of somatotyping that was used to study the physique of individuals in the Gluecks’ sample; the Gluecks merely interpreted the results. The Gluecks concluded that mesomorphy was more predominant among the delinquents, while the control group of nondelinquents contained no preponderance of any single somatotype (Maddan 2010).

 

Besides the Gluecks’ study, two other studies utilized Parnell’s somatotyping procedure. Juan Cortes and Florence Gatti examined the relationship between a person’s physique and the need for achievement, or motivation. They examined 100 delinquent youths and a comparison group of 100 nondelinquents in a high school. In both groups, a significant and positive relationship was found between mesomorphy and motivation; they also found that a significant, but negative, relationship existed between ectomorphy and motivation. Cortes and Gatti concluded that a relationship existed between mesomorphs and the desire to achieve (Maddan 2010).

The association between the physique and height of an individual was mentioned time after time in the literature. Even Sheldon foretold the importance of height and weight in measuring somatotypes noting that with height-weight norms, it will be possible to create a scale of height-weight measures for each different somatotype. The Body Mass Index (BMI) is derived from a person’s height and body weight is used to measure the total body fat. According to the BMI, a person who is an endomorph receives a BMI score of 26 and above, a person who is a mesomorph will receive a BMI score of between 19 and 25, and a person who is an ectomorph will receive a score of less than 19. To test the reliability of the BMI measure, Maddan & colleagues took Sheldon’s original sample data from Varieties of Delinquent Youth and compared the results of Sheldon’s somatotyping technique with the same sample using the BMI scale to determine the individual’s somatotype. The bivariate correlation analyses that were completed to measure the relationship between the two types of somatotype measures showed a strong relationship between Sheldon’s method of somatotyping and the BMI measure. These analyses indicate that the BMI is a reliable measure of somatotyping (Maddan et al. 2008).

  1. Factors which affect Somatotype

The factors which influence somatotype are age, nutrition, smoking habits, physical performance, high altitude, occupation and genetic factors.

  1. Issues with Somatotype Studies in Criminology

There are several limitations to the research on somatotyping and criminality primarily due to the stigma that had been related to conducting research on the link between biological causes of crime in the past. It has been noted that Sheldon’s method of somatotyping was very time consuming and expensive. It took 3 to 4 months to compare the data gathered from the three different pictures of each subject. This time did not include the time it would take to analyze the data with other data in the study, in the case of criminology, delinquency, social, and other structural variables. Also, due to the time period in criminological development, little data could be collected on females. Third, the study on the link between crime and biology, in general, and somatotyping, specifically, is that the results are either mixed or weak (Maddan 2010).

 

The final, and may be the most important, limitation of the somatotyping research before 2008, was the technique that had to be used to measure somatotypes. The main drawback of Sheldon’s method of somatotyping was because Sheldon’s procedure and reformulations of his method required not only subjects be naked, but also that quite a lot of pictures were taken of the naked subjects.

 

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