Baby bust: How friends and colleagues can influence birth rates

Social contagion can help explain falling birth rates – and offers a way out of the demographic trap.

Humans copy one another, and the social contagion effect also leaves its mark on birth rates, says the writer

Published Oct 08, 2026, 06:16 PM

Updated Oct 09, 2026, 05:35 AM

When Susannah McIntyre, 37, hauls her three young sons through her Cambridgeshire village, pedestrians mutter, she says. Cafes seem relieved to see them depart. When she was growing up, it was families with five children that seemed big. But at the local primary school, only two other families have three kids. Now she says she feels like an “outlier”, one who is looked down on with suspicion by people “who regard parenting as a self-indulgent lifestyle choice”.

Across the world, parenthood is on the wane. In Europe, the only child is becoming the norm, with half of families with dependent children having only one. In Britain , the figure is 45 per cent, with just 14 per cent of families having three or more. This is repeated in unexpected places. The United Arab Emirates and Tamil Nadu in India have lower birth rates than Germany. Mexico’s rate has fallen behind the US, where one-child families now outnumber families with two.

Behaviour/Psychology

社会传染效应可以帮助解释出生率下降的原因，并为摆脱人口陷阱提供了一条出路。

作者指出，人类会互相模仿，而这种社会传染效应也会对出生率产生影响。

发布于 2026 年 10 月 8 日下午 6:16

更新于2026年10月9日 上午5:35

37岁的苏珊娜·麦金泰尔带着三个年幼的儿子穿过她位于剑桥郡的村庄时，行人会窃窃私语。她说，咖啡馆似乎也松了一口气，盼着他们离开。在她小时候，五个孩子的家庭才算大户人家。但在当地的小学，只有另外两户人家有三个孩子。现在，她说自己感觉像个“异类”，被那些“认为育儿是一种自我放纵的生活方式”的人用怀疑的眼光看待。

在全球范围内，生育率正在下降。在欧洲，独生子女正逐渐成为常态，一半有子女的家庭只有一个孩子。在英国，这一比例高达45%，只有14%的家庭有三个或三个以上孩子。这种趋势在一些意想不到的地方也出现了。阿拉伯联合酋长国和印度泰米尔纳德邦的生育率低于德国。墨西哥的生育率已经落后于美国，在美国，独生子女家庭的数量已经超过了二孩家庭。

行为学/心理学