The Jews are like everyone else, only more so” is a saying attributed to the late Lionel Blue. Or maybe to Isaiah Berlin. It is paradoxical but true in many spheres. Want the most outspoken defenders of capitalism? Try Milton Friedman or Ayn Rand. Its most visceral critics? Go to Karl Marx or Leon Trotsky. Jews from Moses to Jonathan Sacks have been the greatest advocates of a belief in God, but many of the most ardent atheists of recent times like Christopher Hitchens and Sam Harris have had Jewish backgrounds. So when it comes to demography — matters of population — we should not be surprised that Jews are like everyone else but more so, and thereby are quite unique.

Ashkenazim in Central and Eastern Europe were pioneers of a great demographic transition which went on to sweep the world. Often better educated than their neighbours, they were earlier to adopt the life-preserving habits of modernity to which their religion in any case predisposed them — hand washing (think of al n’tilat yadayim) and bodily hygiene (think of the mikvah). Add a greater likelihood of living in a town and having access at least some medical care and it is not surprising that death rates plummeted as the 19th century progressed. 

For a while, families continued to be large. Combine low mortality with high fertility and you have the sort of population explosion we once witnessed in parts of Europe and are now witnessing in much of Africa. The number of Jews worldwide more than quadrupled between 1800 and 1900.  The great migration of Jews out of the Pale of Settlement to Britain, North America and beyond was taking place at the same time as massive Jewish demographic expansion.

Being at the cutting edge of modernity brings with it the benefits of an early fall-off in death rates and population explosion, but then come smaller family sizes and the flattening-off of population growth. 

Already by the time of the outbreak of the Second World War, fertility was tumbling in many Jewish communities. 

Women were better educated, contraception was increasingly available and Jews were early to adopt the nuclear family. 

In less developed parts of the world, particularly North Africa and the Middle East, Jews were at an earlier phase of their demographic transition and families remained large until well into the 20th century, but for the overwhelmingly Ashkenazi communities of Europe and North America, a population slowdown was already underway when Holocaust reduced millions to ashes.

My own family is a case in point and many readers will be familiar with similar patterns in theirs. My mother was one of two, my father an only child, typical of the small family sizes of the inter-war generation. Even my grandparents — born between the 1880s and 1914 — were ones of just two or three, representative of middle class German Jews of their day. 

But if I go back to the generation of my great grandparents, families of five or six or more were normal.

Since the Second World War, many Jewish communities have been at the forefront of the low fertility trend which has swept the world and is prevalent today everywhere from Bogota to Beijing. 

In what was until recently the world’s largest Jewish community, the United States, Jews had the lowest fertility rate of any major religious community — well below replacement level. 

 In Israel, the fertility rate was initially bolstered by the arrival of Mizrachim from Morocco, Iraq and Yemen, but once arrived in the Promised Land they too started to follow the low birthing pattern of the Ashkenazim who had come earlier.

But then something unexpected started to happen. The developed world — and much of the developing world — followed what seemed like an inevitable path of ever lower birth rates, with countries from Italy to Korea registering not much more than one birth per woman. 

Israel had all the features normally associated with this ultra-low fertility rate: high levels of education among women, high levels of urbanisation, high levels of income. 

Yet from the 1990s Israel started to take a unique turn. Its fertility rate started to rise. Today, the fertility rate in Israel is slightly above three children per woman, compared to around 1.6 and 1.7 in the UK and US and much lower still in countries like Italy and Japan (around 1.3 in both). No other country in the OECD — that is, no other country with a fully developed economy — scores above two. In the early 1980s, for example, the average Iranian woman had more than twice as many children as the average Israeli; today she fewer. If all the world is eventually to get educated and rich, and if that inevitably means family sizes too for one generation numerically to replace the previous one, then in the long term, humanity is doomed. But Israel has shown that the trend can be bucked and that it is possible to combine modernity and prosperity with a healthy level of childbearing.

Certainly the birth rate in of the Charedim in Israel is sky-high, but moderately religious and secular Israelis have much larger families than their counterparts in rich countries in Europe, North America and East Asia. Outside Israel, the turnaround in Jewish demography is more exclusively the work of the strictly Orthodox. In the UK, Charedi women have around seven children each, compared to around two for the rest of the Jewish population; couple that with their negligible out-marriage rate and it is not surprising that some believe that the Charedim will become the Anglo-Jewish majority in the latter half of the current century and are perhaps already responsible for the majority of Jewish births in the UK.  

A similar pattern can be observed in the US, where the Jewish future seems to belong to the strictly Orthodox. Aside from the anomaly that is Israel, Jewish communities in the diaspora today have some of the highest and some of the lowest fertility rates in the world. 

Demography is destiny for everyone, but for Jews even more so. 

Paul Morland is the author of ‘Tomorrow’s People: The Future of Humanity in 10 Numbers’