of height on risk for alzheimer's disease, although this fact could be a result of the genetic overlap between height and intracraneal volume and there are also genetic variants influencing height that could affect biological mechanisms involved in alzheimer's disease etiology, such as insulin-like growth factor 1 (igf-1). nonetheless, modern westernized interpretations of the relationship between height and health fail to account for the observed height variations worldwide. cavalli-sforza and cavalli-sforza note that variations in height worldwide can be partly attributed to evolutionary pressures resulting from differing environments. these evolutionary pressures result in height-related health implications. while tallness is an adaptive benefit in colder climates such as those found in europe, shortness helps dissipate body heat in warmer climatic regions. consequently, the relationships between health and height cannot be easily generalized since tallness and shortness can both provide health benefits in different environmental settings. in the end, being excessively tall can cause various medical problems, including cardiovascular problems, because of the increased load on the heart to supply the body with blood, and problems resulting from the increased time it takes the brain to communicate with the extremities. for example, robert wadlow, the tallest man known to verifiable history, developed trouble walking as his height increased throughout his life. in many of the pictures of the latter portion of his life, wadlow can be seen gripping something for support. late in his life, although he died at age 22, he had to wear braces on his legs and walk with a cane; and he died after developing an infection in his legs because he was unable to feel the irritation and cutting caused by his leg braces. sources are in disagreement about the overall relationship between height and longevity. samaras and elrick, in the western journal of medicine, demonstrate an inverse correlation between height and longevity in several mammals including humans. women whose height is under 150 cm (4 ft 11 in) may have a small pelvis, resulting in such complications during childbirth as shoulder dystocia. a study done in sweden in 2005 has shown that there is a strong inverse correlation between height and suicide among swedish men. a large body of human and animal evidence indicates that shorter, smaller bodies age more slowly, and have fewer chronic diseases and greater longevity. for example, a study found eight areas of support for the "smaller lives longer" thesis. these areas of evidence include studies involving longevity, life expectancy, centenarians, male vs. female longevity differences, mortality advantages of shorter people, survival findings, smaller body size due to calorie restriction, and within-species body size differences. they all support the conclusion that smaller individuals live longer in healthy environments and with good nutrition. however, the difference in longevity is modest. several human studies have found a loss of 0.5 years/centimeter of increased height (1.2 yr/inch). but these findings do not mean that all tall people die young. many live to advanced ages and some become centenarians. in medicine, height is measured to monitor child development, this is a better indicator of growth than weight in the long term. for older people, excessive height loss is a symptom of osteoporosis. height is also used to compute indicators like body surface area or body mass index. height and occupational success there is a large body of research in psychology, economics, and human biology that has assessed the relationship between several physical features (e.g., body height) and occupational success. the correlation between height and success was explored decades ago. shorter people are considered to have an advantage in certain sports (e.g., gymnastics, race car driving, etc.), whereas in many other sports taller people have a major advantage. in most occupational fields, body height is not relevant to how well people are able to perform; nonetheless several studies found that success was positively correlated with body height, although there may be other factors such as gender or socioeconomic status that are correlated with height which may account for the difference in success. a demonstration of the height-success association can be found in the realm of politics. in the united states presidential elections, the taller candidate won 22 out of 25 times in the 20th century. nevertheless, ignatius loyola, founder of the jesuits, was 150 cm (4 ft 11 in) and several prominent world leaders of the 20th century, such as vladimir lenin, benito mussolini, nicolae ceaușescu and joseph stalin were of below-average height. these examples, however, were all before modern forms of multi-media, i.e., television, which may further height discrimination in modern society. further, growing evidence suggests that height may be a proxy for confidence, which is likewise strongly correlated with occupational success. human height throughout history average human height in the eastern mediterranean from the upper paleolithic (before 16,000 bc) period, through to 1996. average adult height by year of birth, world annual change in average female height by year of birth annual change in average male height by year of birth in general, modern humans living in developed countries are taller than their ancient counterparts, but this was not always the case. certain ancient human populations were quite tall, even surpassing the average height of the tallest of modern countries. for instance, hunter-gatherer populations living in europe during the paleolithic era and india during the mesolithic era averaged heights of around 183 cm (6ʹ0ʺ) for males, and 172 cm (5ʹ8ʺ) for females. human height worldwide sharply declined with the advent of the neolithic revolution, likely due to significantly less protein consumption by agriculturalists as compared with hunter-gatherers. during the bronze age, height varied significantly by region. the people of the indus valley civilization were among the tallest in the world, with an average height of 175.8 cm (5ʹ9½ʺ) for males, and 166.1 cm (5ʹ5ʺ) females. the people of ancient egypt stood around 167.9 cm (5ʹ6ʺ) for males and 157.5 cm (5ʹ2ʺ) for females. the ancient greeks averaged 166.8 cm (5ʹ5½ʺ) for males and 154.5 cm (5ʹ1ʺ) for females. the romans were slightly taller, with an average height of 169.2 cm (5ʹ6½ʺ) for males and 158 cm (5ʹ2æ") for females. in the 150 years since the mid-nineteenth century, the average human height in industrialised countries has increased by up to 10 centimetres (3.9 in). however, these increases appear to have largely levelled off. before the mid-nineteenth century, there were cycles in height, with periods of increase and decrease; however, apart from the decline associated with the transition to agriculture, examinations of skeletons show no significant differences in height from the neolithic revolution through the early-1800s. in general, there were no significant differences in regional height levels throughout the nineteenth century. the only exceptions of this rather uniform height distribution were people in the anglo-saxon settlement regions who were taller than the average and people from southeast asia with below-average heights. however, at the end of the nineteenth century and in the middle of the first globalization period, heights between rich and poor countries began to diverge. these differences did not disappear in the deglobalization period of the two world wars. baten and blum (2014) find that in the nineteenth century, important determinants of height were the local availability of cattle, meat and milk as well as the local disease environment. in the late twentieth century, however, technologies and trade became more important, decreasing the impact of local availability of agricultural products. in the eighteenth and nineteenth centuries, people of european descent in north america were far taller than those in europe and were the tallest in the world. the original indigenous population of plains native americans was also among the tallest populations of the world at the time. some studies also suggest that there existed the correlation between the height and the real wage, moreover, the correlation was higher among the less developed countries. the difference in height between children from different social classes was already observed by age two. in the late nineteenth century, the netherlands was a land renowned for its short population, but today dutch people are among the world's tallest with young men averaging 183.8 cm (6 ft 0.4 in) tall. according to a study by economist john komlos and francesco cinnirella, in the first half of the eighteenth century, the average height of an english male was 165 cm (5 ft 5 in), and the average height of an irish male was 168 cm (5 ft 6 in). the estimated mean height of english, german, and scottish soldiers was 163.6 cm (5 ft 4+1⁄2 in) – 165.9 cm (5 ft 5+1⁄2 in) for the period as a whole, while that of irish was 167.9 cm (5 ft 6 in). the average height of male slaves and convicts in north america was 171 cm (5 ft 7+1⁄2 in). the average height of americans and europeans decreased during periods of rapid industrialization, possibly due to rapid population growth and broad decreases in economic status. this has become known as the early-industrial growth puzzle in the u.s. context the antebellum puzzle. in england during the early nineteenth century, the difference between the average height of english upper-class youth (students of sandhurst military academy) and english working-class youth (marine society boys) reached 22 cm (8+1⁄2 in), the highest that has been observed. data derived from burials show that before 1850, the mean stature of males and females in leiden, the netherlands was respectively 167.7 cm (5 ft 6 in) and 156.7 cm (5 ft 1+1⁄2 in). the average height of 19-year-old dutch orphans in 1865 was 160 cm (5 ft 3 in). according to a study by j.w. drukker and vincent tassenaar, the average height of a dutch person decreased from 1830 to 1857, even while dutch real gnp per capita was growing at an average rate of more than 0.5% per year. the worst decline was in urban areas that in 1847, the urban height penalty was 2.5 cm (0.98 in). urban mortality was also much higher than in rural regions. in 1829, the average urban and rural dutchman was 164 cm (5 ft 4+1⁄2 in). by 1856, the average rural dutchman was 162 cm (5 ft 4 in) and urban dutchman was 158.5 cm (5 ft 2+1⁄2 in). a 2004 report citing a 2003 unicef study on the effects of malnutrition in north korea, due to "successive famines," found young adult males to be significantly shorter. in contrast south koreans "feasting on an increasingly western-influenced diet," without famine, were growing taller. the height difference is minimal for koreans over forty years old, who grew up at a time when economic conditions in the north were roughly comparable to those in the south, while height disparities are most acute for koreans who grew up in the mid-1990s – a demographic in which south koreans are about 12 cm (4.7 in) taller than their north korean counterparts – as this was a period during which the north was affected by a harsh famine where hundreds of thousands, if not millions, died of hunger. a study by south korean anthropologists of north korean children who had defected to china found that eighteen-year-old males were 13 centimetres (5 in) shorter than south koreans their age due to malnutrition. the tallest living man is sultan kösen of turkey, at 251 cm (8 ft 3 in). the tallest man in modern history was robert pershing wadlow (1918–1940), from illinois, united states, who was 272 cm (8 ft 11 in) at the time of his death. the tallest woman in medical history was trijntje keever of edam, netherlands, who stood 254 cm (8 ft 4 in) when she died at the age of seventeen. the shortest adult human on record was chandra bahadur dangi of nepal at 54.6 cm (1 ft 9+1⁄2 in). an anecdotal article titled "ancient american giants" from the 14 august 1880 edition of scientific american notes a case from brushcreek township, ohio, when dr. j. f. everhart supervised a team that discovered ancient clay coffins within a mound which were reported to contain skeletons of the following length: 8 ft 0 in (2.44 m) woman with a child 3.5 ft 0 in (1.07 m), a second coffin with a 9 ft 0 in (2.74 m) man and 8 ft 0 in (2.44 m) woman, a third coffin with a 9 ft 4 in (2.84