How much taller are you than your great-grandfathers and great-grandmothers? Most likely, considerably taller.
According to data from the research resource Our World in Data, young people around the world today are, on average, 10 cm taller than their ancestors from a century ago.
A 2016 study comparing people born in 1896 and 1996 showed that women in South Korea and men in Iran had grown the most – by 20 cm and 17 cm respectively.
This is due to improved nutrition, reduced disease, vaccination and many other factors, says Dr Aravinda Guntupalli, a senior lecturer in global health at the University of Aberdeen in Scotland.
However, the history of human height has not always been a steady upward trend. Over the millennia, diet, wars, disease and other large-scale societal changes have led to fluctuations in our height.
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A look back at history
According to researchers, height can help gauge living standards in cases where other historical or statistical data are lacking.
“Height is a good indicator of well-being,” says Dr Matthias Blum, an economic historian and emeritus professor at Queen’s University Belfast in Northern Ireland.
Research shows that between 80 and 90 per cent of a person’s height is determined by genetics.
At the same time, the extent to which this genetic potential is realised is significantly influenced by living conditions, in particular nutrition, health and the environment during childhood.
The remainder is determined by factors such as diet, susceptibility to disease, childhood conditions and access to healthcare.
‘Greater height reflects a higher standard of living,’ says Bloom.
He explains that, to account for genetic differences, researchers analyse average height across large populations to identify trends not reflected in other indicators, such as GDP.
According to Bloom, data on height can show how well the basic needs of the population were met during different historical periods, and are therefore a valuable tool for studying the well-being of societies.
Did agriculture lead to shorter stature?
According to Bloom, two turning points can be identified in history.
The first occurred during the Neolithic Revolution, when, approximately 12,000–10,000 years ago, people transitioned from hunting and gathering to agriculture.
To trace trends from those distant times, researchers rely on data from human skeletons, although this information has its limitations. However, most scientists agree that the spread of agriculture led to a decrease in average human height.
A 2022 study estimated that, taking genetic differences into account, Neolithic people were on average 2.8 cm shorter than would be expected compared with people from the pre-Neolithic era.
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The transition to agriculture ensured a more stable food supply, but did not necessarily improve nutrition.
The diet of hunter-gatherers contained more animal-based foods, and, according to Bloom, this was crucial.
‘It’s a question of whether you’re starving or not. From that point of view, having more animal-based foods in your diet is a good idea, because you need to get those amino acids from somewhere,’ he says.
As well as a better diet, hunter-gatherers had another advantage: they could simply leave their homes and move elsewhere, notes Bloom. In contrast, farmers did not have this option.
They suffered from infectious diseases and ‘were forced to work hard, look after their homes and livestock, and live alongside animals’.
Over the following millennia, average height fluctuated across different regions, but, according to Bloom, these changes were often short-lived.
‘If you look at long periods of time, there is no clear trend towards an increase or decrease in height. There are years of famine, there are wars, but afterwards the population recovers,’ he says.
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Some crises had unexpected consequences. Researchers estimate that following the ‘Black Death’ – the plague pandemic that claimed the lives of up to half of Europe’s population in the mid-14th century – average height increased.
Research carried out by Guntupalli and her colleagues, based on an analysis of skeletal remains in England, showed that in the early 14th century, the average height of the population was around 170 cm. By the early 15th century, it had risen to approximately 174 cm.
‘This may have been due to higher wages, as the labour shortage gave people more opportunities to bargain, and they were likely able to improve their standard of living.’
‘A complex of innovations’
According to Bloom, the second significant change in people’s height occurred as a result of the Industrial Revolution, which began in Great Britain in the 18th century and subsequently spread to other parts of the world.
Industrialisation led to a shift in the economy from agriculture to industry. It became the driving force behind mass urbanisation, the introduction of cutting-edge technologies and the expansion of international trade.
As a result, people became taller, but this did not happen overnight.
Living conditions in the early stages of industrialisation ‘did not promote good health’, notes Guntupalli. Poor sanitary conditions, overcrowded housing and gruelling labour in factories across various countries led to a decline in average height during the first decades of the industrial era.
Bloom notes that in large industrial centres, people even took turns sleeping in the same bed.
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It was only later, with rising incomes and the introduction of more comprehensive public health measures, that average height began to increase significantly.
Bloom attributes this to improvements in sanitation, housing and nutrition, as well as the emergence of new medical technologies.
“It’s a whole range of innovations working in tandem,” he says.
Although South Korea underwent industrialisation later, its rapid economic development was accompanied by one of the most impressive increases in average height recorded over the past century: men have grown taller by an average of 15 cm, and women by 20 cm, according to a 2016 analysis.
Has humanity reached its peak?
According to Our World in Data, the average height of people born in 1996 is 171 cm for men and 159 cm for women.
According to Bloom, in highly developed countries, further growth in income, labour productivity and the volume of goods and services produced no longer seems to lead to an increase in the average height of the population.
The reasons for this remain unclear. Some researchers suggest that the populations of such countries may already have reached the maximum height determined by genetics. Others attribute this to the growing popularity of fast food and a sedentary lifestyle.
Bloom notes that in the future, we may need to look for new indicators of ‘biological standard of living’ beyond height.
For example, the spread of vegan and vegetarian diets will not necessarily lead to an increase in average height, but may offer other benefits, such as improved health and greater environmental sustainability.
As for the world as a whole, Guntupalli is sceptical about the prospects for a further increase in average height. She points to shortages of food and fuel, as well as the ‘very pronounced inequality’ that exists today.
In low- and middle-income countries, ‘there are higher levels of stunting, and the shortest people in these countries are the poor,’ she says. Stunted growth refers to a condition where children are too short for their age and subsequently become short adults.
Furthermore, according to Guntupalli, extreme weather events such as droughts and floods are having a negative impact on food production and the availability of milk and other animal-based products.
“Funding for global health programmes is also being cut, which is affecting many vaccination, nutrition and refugee aid programmes,” she adds.
Guntupalli believes that under such conditions, inequality in average growth will be evident not only between rich and poor countries, but also within societies themselves.
“We live in an unequal world,” she says.