Here is how the cliodynamician Peter Turchin, in his book War and Peace and War (which I reviewed here), describes the outcomes of different pit-fight scenarios between the Romans and the Gauls:

Romans held no physical or technological advantage over the peoples they conquered. An average Roman was smaller and weaker than an average Gaul. In a one-to-one duel, an average Roman would most likely lose to an average Gaul. On the other hand, a hundred Romans could hold even against a hundred of Gauls, and ten thousand Romans would easily defeat a Gallic army many times their number.

Upon inquiry, it emerged that this assessment wasn’t backed up by statistical evidence:

@akarlin88 @quaerite Yes, this is from my War and Peace and War. But it's not a quantitative model, or a result from data analysis… — Peter Turchin (@Peter_Turchin) April 9, 2016

Even so, the stereotype that Northerners are stronger than Southerners seems to be widespread in both fiction and more serious works:

Harry Turtledove – Give Me Back My Legions!:

Arminius smiled. “Well, maybe we would have.” He didn’t feel like arguing. But he also didn’t believe Chlodevegius. One German had an excellent chance against one Roman. Ten Romans had the edge on ten Germans. A hundred Romans would massacre a hundred Germans.

Stephen Williams – Diocletian and the Roman Recovery:

With the primitive, wandering farmer-warrior ethos in which each tribe was ready to expand into the space of its nearest neighbour, the Germans could recover quickly from all but the most punitive defeats. Man for man they were physically stronger than the Romans and certainly as brave: Their fierce fighting qualities had long compelled admiration: Tacitus, prophetically, saw in their warlike freedom a new reservoir of enormous energies which could have profound consequences for the Roman future.

But is it actually true?

This post is a quick survey of physical strength differences from an HBD perspective.

Race Differences in Physical Strength

1. Araujo, Andre et al. – 2010 – Lean mass, muscle strength, and physical function in a diverse population of men

Black diamonds – Blacks; Black triangles – Whites; Gray squares – Hispanics

Physical strength of Whites and US Blacks are really similar.

2. Dodds, Richard et al. – 2016 – Global variation in grip strength, A systematic meta-analysis

There are obvious “Flynn” effects with respect to strength as well as IQ – the developed countries are a lot stronger than Africa (which was represented by Nigeria), which suggests that possible Flynn gains to strength are on the order of 1-1.5 S.D.

3. Leong, Darryl et al. – 2015 – Prognostic value of grip strength

This is more interesting, and really quite striking. It would appear that the weakest men (South Asians) do not have a stronger hand grip than the strongest women (Europeans).

PS. So much for the Pakistani martial race theory…

Though seldom used in today’s context, it has been alleged that Pakistan Military believed in the concept of martial races, and thought that they would easily defeat India in a war, especially prior to the Indo-Pakistani War of 1965. Based on this belief in martial supremacy, it was popularly said that one Pakistani soldier was equal to four to ten Hindus or Indian soldiers, and thus numerical superiority of the foe could be overcome… Defence writers in Pakistan have noted that the 1971 defeat was partially attributable to the flawed ‘martial races’ theory which led to wishful thinking that it was possible to defeat the Indian Army based on the theory alone.

4. Andersen Ranberg, Karen et al. – 2009 – Cross National Differences in Grip Strength among 50yo Europeans

Moreover, the Germanics really are significantly stronger than the Mediterraneans. The average Germanic seems to be around 15 years “younger” than the average Italian or Spaniard in terms of hand grip strength. These are remarkably big differences, around 1 S.D.’s worth. Average German, Swede, or Pole might have a 15 SQ (strength quotient) advantage over the average South European.

OTOH, the Italians and Spaniards also happen to be the two longest-lived European nations. (This is something of a pattern, too).

5. Mathieson, Iain et al. – 2015 – 8000 years of natural selection for height in Europe (see Razib Khan’s blog post)

Note that Central Europe Neolithic to Bronze Age and especially the Steppe strongly selected for height.

Even today, based on personal experience, you will observe many taller, burlier men in Germanic and Slavic Europe than you would in the Mediterranean.

Sex Differences in Physical Strength

For context, there is a ~2.5 S.D. difference in male and female grip strength.

1. Leyk, D. et al. – 2007 – Hand-grip strength of young men, women and highly trained female athletes (see Razib Khan’s blog post)

2. There is also this famous graph which was making the rounds on Reddit a year ago.

Women have around 60% of the hand grip strength of men. Huge difference… but remarkably, seems to be about equal to the difference between developed Anglo-German/Slavic Europe and the Indian subcontinent!

PS. Why do so many of these studies focus on grip strength? Because it is easy to measure, changes the least as people age (hand grip is the last to go), and is exercised more or less universally.

The Strength of Nations

My best guess is that in terms of S.D.’s it goes something like this in terms of hand grip strength (Flynn! denotes members of those ethnicities that dwell in First World environments).

+1 Icelanders

+0.5 Steppe!East Asians (i.e.Mongols)

0 Balto-Slavic-Germanics, Flynn!WestAfricans

-.5 East Asians

-1 Mediterraneans, Flynn!Indians, WestAfricans

-2 Indians Explanations of Icelanders, Mongols, and Indians follow below.

Prominent Outliers

Two nations in particular seem to be superlative in terms of physical strength relative to their racial groups:

Hafþór Björnsson (better known as The Mountain): World’s strongest man ever?

1. Icelanders, with a mere 300,000 people, dominate the world strongman competitions. They have won 9 Gold medals, more than any other country other than the US, which has won 11 (and has ONE THOUSAND times its population).

In January 2015, at the World’s Strongest Viking competition held in Norway, Hafþór carried a 10-metre-long (33 ft), 650-kilogram (1,430 lb) log for five steps, thus breaking a 1,000-year-old record set by Orm Storolfsson.

Unfortunately, Orm Storolfsson broke his back performing this feat. Still, considering that the Icelandic population one millennium ago was ten times lower at 30,000, and they had yet to be supercharged by bodily Flynn Effect, perhaps the human race was at its genomic peak of physical strength in Iceland 1,000 years ago.

Agriculture is more of an aerobic activity, so explosive physical strength may have been selected against ever since.

Icelandic women have also won four years of the past decade’s worth the Crossfit Games.

2. The Mongols, with just three million people, dominate sumo wrestling in Japan. (In fairness, the Japanese seem to be physically smaller than other East Asians, so they are probably weaker than Koreans and northern Chinese).

There is also the historical record of their military achievements.

Although these factors were mainly logistical and political, one consideration that is often neglected is that the ketogenic, steppe-forged Mongols may have also been physically stronger and more vital than their grain-eating bugman foes.

Jack Weatherford – Genghis Khan and the Making of the Modern World:

The Chinese noted with surprise and disgust the ability of the Mongol warriors to survive on little food and water for long periods; according to one, the entire army could camp without a single puff of smoke since they needed no fires to cook. Compared to the Jurched soldiers, the Mongols were much healthier and stronger. The Mongols consumed a steady diet of meat, milk, yogurt, and other dairy products, and they fought men who lived on gruel made from various grains. The grain diet of the peasant warriors stunted their bones, rotted their teeth, and left them weak and prone to disease. In contrast, the poorest Mongol soldier ate mostly protein, thereby giving him strong teeth and bones. Unlike the Jurched soldiers, who were dependent on a heavy carbohydrate diet, the Mongols could more easily go a day or two without food.

3. Conversely, the Indians really might be the physically weakest race:

Only 5 medals. Record-setting (3 in Beijing, 0-2 in all previous Olympics) but that’s still atrocious for a country of 1.2 billion people – even a poor and malnourished one. Michael Phelps alone has won almost as many Gold medals as India has done as a nation for as long as the Olympics existed.

But the reasons for this become clearer when you consider that the average Swedish or Polish woman is probably about as strong as the average Indian male. And the average Icelandic woman might even be outright stronger…

The Indians also accumulate the most body fat for every unit of BMI.

Of course malnutrition is still a factor. Once that is solved and India gets its bodily Flynn effect, the average Indian male will surpass the Swedish and probably the Icelandic woman. And given the much higher S.D. of men, the stronger Indian men will of course be much stronger than the European women.