Expert Analysis: Why Do People Have Different Constitutions?

There are many factors that affect the differences in human constitution. Nutrition, education, physical exercise, and healthcare all influence one’s constitution, but the primary influencing factors fall into three major categories: genetic factors (inborn), ecological factors (or environmental factors), and personal factors. Ecological and personal factors are acquired, while personal factors are also under one's own control. Thus, in a sense, the quality of a person’s constitution after birth depends on themselves. The WHO has announced that 60% of an individual's health and longevity depend on themselves, and 15% on genetics.

Changes in the ecological environment can lead to adaptive evolution in organisms, resulting in alterations in morphology, function, metabolism, immunity, disease susceptibility, body composition, and physical fitness. The evolution from apes to humans is the result of ecological adaptation due to changes in the living environment. At that time, the Earth’s climate was dry, and forest areas were shrinking, forcing humans to come down from the trees to live on the ground. This led to a reduction in the number of cervical and lumbar vertebrae, a more compact torso, and longer limbs. The spine developed four physiological curves as adaptive changes. In tropical regions, spiral-shaped hair helps dissipate heat and protect the brain; in cold regions, high nasal bridges and narrow nasal cavities help warm cold air. People living in the Arctic have a barrel-shaped thorax with large bone cavities to adapt to low oxygen levels, enhancing hematopoietic capacity. Wide mouth fissures, large lip mucosa surface areas, and narrow, tall head shapes help accelerate water evaporation, adapting to intense sunlight and tropical living. A large, prominently protruding nose benefits those living in areas with thin air—enlarged nostril cross-sections and nasal cavity volumes create a greenhouse effect to adapt to cold environments. Environments with strong winds and sand or snowy landscapes have contributed to the formation of eye wrinkles.

Culture is also a form of human socio-ecological adaptation to the environment. Humans use culture to adapt to the environment and also to transform it. From the agricultural civilization (also known as the Yellow Civilization) of the farming era, to the Black Civilization of the industrial age, and now, where humans seek to live in harmony with nature, we see the emergence of Green Civilization. These three civilizations have had a significant impact on human differences. From the simplest increases in population size and density, to growth and development, changes in disease spectrum, and extended lifespan—all are related to ecological changes (see Tables 5, 6, 7). Susceptibility to certain diseases may be due to cultural and/or ecological reasons rather than biological differences.

Constitution is dynamic, changeable, and adjustable. It can develop in a positive direction or a negative one. Which direction it takes depends on oneself. Overuse of hormones, misuse of antibiotics, improper health supplements, skipping breakfast, picky eating, overly sweet, salty, or greasy food, dependence on air conditioning, sedentary work, constant computer use, prolonged mahjong sessions, lack of physical exercise, poor mental health, and similar behaviors can, over time, lead to a decline in constitution, causing issues such as cervical spondylosis, metabolic disorders, and nervous system dysfunctions.

People’s ways of dressing, eating, living, traveling, and entertaining differ across societies. From ancient times to the present, humanity has gone through lifestyles in primitive, ancient, modern, and contemporary societies. Changes in lifestyle have led to shifts in health perspectives, disease spectra, and mortality patterns. For various reasons, each person has their own distinct lifestyle—some healthy, some not. Over time, these accumulate and result in differing constitutions. Good lifestyles naturally lead to better health and stronger constitutions; the opposite leads to illness and weakened constitutions. In this sense, the quality of a person’s constitution is largely determined by themselves. Constitution and health are mutually causal—robust constitutions have strong resistance and suffer from fewer or no illnesses, and vice versa.

In modern society, the rapid development of productivity and advanced science and technology have significantly improved living comfort and quality of life. Under such a lifestyle, the abundance, convenience, satisfaction, and pleasure derived from material life, new value concepts, strong consumer awareness, faster-paced life, ecological degradation, increased social conflicts, strained interpersonal relationships, and greater psychological stress have led to unhealthy lifestyles: unhealthy diets (excessive drinking, high sugar, high fat, high salt, refined foods, etc.), lack of physical exercise, psychological tension and stress, strained interpersonal relationships, loneliness and social isolation, gambling addiction, drug addiction (smoking, drug use, etc.), inappropriate sexual behavior, poor hygiene habits, and more, which have triggered a series of lifestyle-related diseases. In the 1950s, 24% of deaths were caused by lifestyle diseases; by the late 1990s, that figure had risen to 70%.