Criminology - U2 - Sheldon's Somatotype Theory

Somatotype Theory & Constitutional Psychology

William Sheldon's somatotype theory links body type to personality traits. He classified people into three body types: endomorph, mesomorph, and ectomorph. This formed the basis of constitutional psychology, which posits that physical characteristics can influence an individual's psychological makeup and behaviour.

Endomorph

A body type characterised by being round and soft. Associated with a "viscerotonic" personality: relaxed, comfortable, and extroverted.

Mesomorph

A body type characterised by a muscular and square physique. Associated with a "somotonic" personality: active, dynamic, assertive, and aggressive. Mesomorphs are also considered more likely to engage in crime due to their assertiveness and physical attributes.

Ectomorph

A body type characterised by a slim, fine-boned physique. Associated with a "cerebrotonic" personality: introverted, thoughtful, inhibited, and sensitive.

Sheldon's Somatotype Classification

Sheldon's system classifies people into three body types: endomorph, mesomorph, and ectomorph. A somatotype score is based on the relative amount of each type, ranging from 1 to 7 (e.g., 444 is a balanced physique).

Three-Digit Somatotype Number

Sheldon's somatotype classification uses a three-digit number to describe an individual's body type. Each digit represents a body type on a scale from 1 to 7: the first digit refers to endomorphy (roundness, softness), the second digit refers to mesomorphy (muscularity, square physique), and the third digit refers to ectomorphy (slimness, fine-boned physique). For example, 711 would be highly endomorphic, with minimal mesomorphy and ectomorphy, while 171 would be highly mesomorphic with minimal endomorphy and ectomorphy.

Mesomorphs & Crime

Sheldon suggested mesomorphs were more likely to engage in criminal behaviour due to their assertive, risk-taking nature and physical traits that favour dominance and aggression.

Sheldon's Correlation Study

In a study comparing college students and delinquents, Sheldon found delinquents had a higher average mesomorphy score (4.6) compared to college students (3.8), linking mesomorph traits to a higher likelihood of criminal behaviour. Mesomorphy was measured on a scale of 1 to 7, with 1 indicating minimal mesomorph traits (low muscularity, thin physique) and 7 indicating maximum mesomorph traits (high muscularity, square physique).

Body Type & Personality

Sheldon believed that body types influenced personality traits. Endomorphs were seen as extroverted and relaxed, mesomorphs as active and competitive, and ectomorphs as introverted and intelligent.

The Varieties of Human Physique

In his 1940 book The Varieties of Human Physique, Sheldon explained his somatotype theory, showing how body types could predict personality traits and criminal tendencies. He based his findings on extensive observations and photographic analysis.