According to a new research study, having children may adversely impact your social circle. The equation they've devised is: Lose One Friend For Every 2 Kids.
The British study shows that having offspring makes us lose friends at the rate of 2 kids to one pal, as parents fall back on family and professional helpers.
The findings are part of a large-scale investigation, commissioned by Co-operatives UK, into how neighbourly and friendly the British are.
Overall, the study presents a picture of Britain becoming a lonely and atomised society of people who have more acquaintances but fewer close friends.
"There are fewer friends, more loneliness, less contact with people around you unless you are proactive and go out to engage with people," the Telegraph quoted Ed Mayo, secretary-general of Co-operatives UK, an association representing co- operative enterprises, as saying.
"There is not that bedrock of the garden fence to fall back on. Different patterns of family life and work have all contributed," he added.
For the research, YouGov polled 2,167 adults for Co- operatives UK using questions based largely on the 1982 Sunday Times/Mori study.
The results were then analysed by Mayo and compared with the earlier findings.
And it has emerged that the average number of neighbours known to respondents has fallen sharply.
In 1982, nearly half believed they knew by name at least 11 neighbours and a quarter knew 20 or more.
Currently, even the most neighbourly Britons - those in Scotland - know an average of only 8.4 neighbours.
There has also been a decline, although less severe, in the number of friends, down from an average of 5.1 per person to 4.6.
This has been accompanied by a stark rise in loneliness.
In 1982, 76 per cent of people said they never felt lonely, but this year the figure had fallen to just 32 per cent.
Mr Mayo described this finding as "very, very stark".
He said: "People seem to have a wider circle of acquaintances and shallow friendships, particularly online, which cuts down the number to whom they feel really close."
The average number of close friends for people with no children is 4.7 and this gradually declines until those who have three children have just 3.5.