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Psychology and Human Nature

Probable / Possible "Scientific endorsement"
of Tripartite Human Nature Theory

Two instances of science-based - probable / possible - 'effective endorsement' of a Tripartite Soul theory of Human Nature will now be briefly considered.

In each case a link will be provided to fuller coverage on our partner site -

The New York Longitudinal Study

In 1956 a child psychiatrist named Dr. Stella Chess, together with her husband Dr. Alexander Thomas, a former director of psychiatry at Bellevue Hospital Center, embarked on what became widely-known-of, influential, and commented upon, as the New York Longitudinal Study.

Longitudinal studies are observational research method in which data is gathered for the same individuals who are the subjects of that study over years or even decades.
Such observational research method are not infrequently adopted in medicine, psychology and sociology, as, in those fields they are held to be well-suited to allowing researchers to investigate and report on changes detected over time.

In this case Dr. Chess and Dr. Thomas, fully assisted by Herbert G. Birch and Margaret E. Hertzig, set out to follow the development of more than one hundred and thirty infants as they went on to become children, teenagers and adults.

The New York Longitudinal Study focused on a number of dimensions of behaviour and concluded that people could be described as being "easy," "difficult" or "slow to warm up".

These findings were published in an influential academic context, the American Journal of Psychiatry, in 1960.

The research did suggest that suchy categorisation was not, in fact, fixed and that adjustments could well occur in response to changes in environment.
Nevertheless, the results of the study led by Dr. Chess and Dr. Thomas resulted in the popularization of a widely influential theory that children are born with distinct temperaments that can powerfully affect their outlook and are, broadly-speaking, rather enduring in the individual who has been considered to be "easy," "difficult" or "slow to warm up".

More detail at

The New York Longitudinal Study
Dr. Stella Chess & Dr. Alexander Thomas
personality types - temperament traits

William Sheldon on
Constitutional psychology personality theory

William Herbert Sheldon, working in the 1940's, overtly associated human body types with human temperament types.

According to Sheldon:

Tend to be physically plump and have relaxed, out-going temperaments.

Tend to have stong / athletic physiques and in terms of temperament be relatively active, adventurous, courageous - and potentially aggressive.

Tend to have smaller and slight physiques and are inclined to be self-conscious, reserved, thoughful and socially restrained.

Sheldon's suggestions are generally viewed as rather controversial in academic circles but nevertheless seem to attract a degree of popular acceptance.

More detail at

Dr. William Sheldon on
Constitutional psychology personality theory

Several truly notable authorities
endorse Tripartite Soul Theory

Key Socratic Dialogues from
Book 4 and Book 9 of Plato's Republic

Plato's Ideal State       Plato's Chariot allegory      

Philosophy - Eastern and Western & 'Tripartite' Human Nature

FIVE major World Religions & 'Tripartite' Human Nature