Correlations in fertility across generations: can low fertility persist?
Authors:Martin Kolk, Daniel Cownden and Magnus Enquist
Journal:Proceedings of the Royal Society B
A study published in Proceedings of the Royal Society B reveals the possibility for a reversal of the twentieth-century decline in fertility.
Although the world population has now risen beyond 7 billion, fertility has declined over the last 200 years with women bearing fewer children on average than in the past. This decrease, which scientists call the ‘fertility transition’, has been especially dramatic in the developed world where fertility dropped by more than half between the 1850s and early 1900s as people began having smaller families.
Demographers have also reported an increasingly significant link between the number of children a women might have and the number her children will have. As well as inheriting genetics from our parents we can inherit cultural preferences which could explain this link. However, the rapid drop in fertility over the past two centuries suggests a faster change than could be caused by parental influence alone. Scientists suggest that other role models must also influence the fertility choices of an individual.
A team of scientists at Stockholm University set about making a mathematical model to show how these factors could influence overall fertility rates. In particular they were interested to see if the trend of low fertility rates would last or if the number of children families have might be set to increase.