Tallness: too short for my age

Exceptional height is usually due to gigantism or dwarfism. Adult height for one sex in a particular ethnic group follows more or less a Gaussian distribution or bell curve, although with some individuals lying several standard deviations away from the mean. Height or tallness is determined by the interaction of genes and environment. Final adult height may be attained anywhere from the early teens to early 20s, although it is most commonly reached during the mid teens for females and late teens for males. A person’s height also varies over the course of the day, by an average of 19 mm gradually shrinking, as the spine compresses over the course of a day, and stretching back out overnight. Many young people are concerned if they are too short or too tall for their age, so it would be nice to know more about human normal average height.

Changes in human height

Human height is regulated by many factors we could explain. Since the development of modern medicine and plentiful nutrient-rich food in the developed world average height has increased dramatically during last years. Nutrition is the most important factor in determining height. Height records from military records and other documents can be used to quite accurately compare nutrition and height in various eras. Evidence has shown that height decreased in Britain in the early nineteenth century, before beginning its long increase around mid-century, but increase in height has not been constant. The European Middle Ages was an era of tallness with men of above six feet, which is 1.83 m was considered unremarkable. In Europe human height reached its nadir at the start of the 19th century. Until the general rise in human health the accompanying trend was a height decline. Europeans in North America were far taller than those in Europe in the eighteenth and nineteenth centuries. In fact they were the tallest in the world. The original indigenous population was also among the tallest populations of the world at the time, but several nations, indeed many nations in Europe, have now surpassed the US in terms of average stature. It was particularly the Netherlands and Scandinavian nations. The most markedly is the Netherlands where average height has increased at the greatest rates. For instance: the Netherlands was in the late nineteenth century a land renowned for its short population. However, today it has the tallest average in the world with young men averaging 1.83 m tall. The Dutch are now well known in Europe for extreme tallness, and increase has been so dramatic that various things have been redesigned to fit the much taller frames. In contrast, average male height in impoverished Vietnam and North Korea remains comparatively small at 5 ft 4 in, or 1.63 m, and 5 ft 5 in, or 1.65 m respectively. Currently, young North Korean males are actually significantly shorter, so this contrasts greatly with the extreme growth occurring in surrounding Asian populations with correlated increasing standards of living.

Human growth

The study of human growth is known as auxology. Growth and height have long been recognized as a measure of the health and wellness of individuals, hence part of the reasoning for use of growth charts. For individuals growth trends are tracked for significant deviations and growth is also monitored for significant deficiency from genetic expectations. Genetics is a major factor in determining the height of individuals. However, it is far less influential in regard to populations. Average height is increasingly used as a measure of the health and wellness, standard of living, and quality of life of populations. Attributed as a significant reason for the trend of increasing height in parts of Europe is the egalitarian populations. There, proper medical care and adequate nutrition are relatively equally distributed. Changes in diet or nutrition and a general rise in quality of health care and standard of living are the cited factors in the Asian populations. Average height in the United States has remained essentially stagnant since the 1950. Severe malnutrition is known to cause stunted growth in North Korean, portions of African, certain historical European, and some other populations. Diet, especially such things as junk food provoke health problems such as obesity. Exercise, fitness, pollution exposure, sleep patterns, climate, and even happiness or psychological well-being are other factors that can affect growth and final height. Height is determined by the complex interactive combination of both genetics and environment. Genetic potential plus nutrition minus stressors is a basic formula for human growth. Humans grow fastest as infants and toddlers, and then during the pubertal growth spurt. A slower steady growth velocity occurs throughout childhood between these periods. Some slow, steady, declining growth after the pubertal growth spurt levels off is common for most of the people. These are also critical periods where stressors such as malnutrition, or even severe child neglect, have the greatest effect. Conversely, if conditions are optimal then growth potential is maximized. In addition, there is catch-up growth, which can be significant for those experiencing poor conditions when those conditions improve. Moreover, the health of a mother throughout her life, especially during her critical periods, and of course during pregnancy, has a role for growth and human tallness in future. A healthier child and adult develops a body that is better able to provide ideal and optimal prenatal conditions. The pregnant mother’s health is important as gestation is itself a critical period for an embryo and fetus. Some problems affecting height during this period are resolved by catch-up growth assuming childhood conditions. Moreover, there is an accumulative generation effect such that nutrition and health over generations influences the height of descendants to varying degrees. The precise relationship between genetics and environment and exact role of genetics itself is complex and uncertain. Human height is both of moderately high phenotypic plasticity and is highly heritable since height is a multigenic trait. There are substantial relationships in the heights among biological families. The heights of parents and family are a good predictor for the height of their children. Environmental influences are most pronounced if they are highly favorable or unfavorable to growth. That is especially when environmental influence occurring during critical periods and when continuing multigenerationally. Genetic profile or genotype provides potentialities or proclivities, which interact with environmental factors throughout the period of growth resulting in phenotype in final adult height. Essentially, the developing body devotes energy to growth after other bodily functions are completely satisfied. Asian populations were once thought to be inherently shorter, but with the increases in height in East Asian nations such as China and South Korea as diet changes, it now seems that humans as a species probably possess a roughly similar genetic height potential. It seems that thus a predictive genotypic basis for height differentiation has not yet evolved.

Height abnormalities

Most intra-population variance of height is genetic nature, where short stature and tall stature are usually not a health concern as you could think. If the degree of deviation from normal is significant, hereditary short stature is known as familial short stature. Tall stature is known as familial tall stature. Confirmation that exceptional height is normal for a respective person can be ascertained from comparing stature of family members and analyzing growth trends for abrupt changes among other people. There are also various diseases and disorders that cause growth abnormalities. Most notably, extreme height may be pathological, such as gigantism, which is very rare. Gigantism is resulting from childhood hyperpituitarism, and dwarfism, which has various causes. Rarely, no cause can be found for extreme height, while very short persons may be termed as having idiopathic short stature. Tallness has been suggested to be associated with better cardio-vascular health and overall better than average health and longevity. However, height may not be causative of better health and longevity. Some other studies have found no association, or suggest that shorter stature is associated with better health. On the other hand being too tall can cause awkward situations in society and not being able to fit into society at all. Height often plays a crucial role only in sports. For most sports, height is useful as it affects the leverage between muscle volume and bones towards greater speed of movement of these people. It is most valuable in sports like basketball and volleyball. In these sports, short players are well above average in height compared to the general population. In some sports, such as horse racing, auto racing, and gymnastics, smaller frame is more valuable. In other sports, the role of height is specific to particular positions, for example in soccer, a tall goalkeeper is at an advantage because he has a greater armspan and can more easily jump higher. Therefore, one will rarely, if ever, see a short goalkeeper in professional soccer. In rugby union, lineout jumpers are usually the tallest players on the pitch, as this increases their chance of winning clean ball. In the same time, scrum-halves are usually relatively short.