People hate it when mothers try to pull rank on others just because they've given birth
The best-known quotation from the economist John Maynard Keynes was: "In the long run, we are all dead." Critics of Keynes' more left-wing approach to capitalism have claimed that he said this because he was childless. A man with children and grandchildren would not have dismissed the long perspective so easily: he'd have been thinking of his descendants.
Keynes was indeed childless, although he and his wife, the ballerina Lydia Lopokova - whom he had married, happily, after a promiscuously homosexual youth - had had a stillborn baby. But it's a little unkind to suggest that his childlessness accounted for his theory of "the long view" in economics. Many a childless person has had a careful sense of leaving a prudent legacy for the future. Some of our richest cultural legacies come from communities of monks, anxious to preserve for the future that which they have drawn from the past.
And when the British Conservative leadership candidate Andrea Leadsom claimed recently that she had a greater stake in the future than the childless Theresa May, it proved her undoing. Her insensitive remark went viral, and she attracted such a global degree of odium that she felt she had to step down from her candidature.
There's a basic lesson here: people - especially other women - hate it when mothers try to pull rank on others, just because they have given birth.
There's a wider application, too: people who are not parents are both bored and offended when parents - and grandparents - blather on proudly about their darling little poppets and the clever things they say and do.
There should be a social rule: unless specifically invited to do so, never talk about your children or grandchildren in mixed company. Never pull out a picture from your smartphone to show off the little dears (unless specifically invited to do so). Never begin a sentence "speaking as a mother/father/grandparent".
All parents and grandparents have done this, and it may be acceptable when parents or grandparents are gathered together, but it can be enraging to those who are not parents or grandparents, who feel an immediate hostility to the "smug" assumptions made by mothers, fathers and other progenitors of the species.
Call it Leadsom's law. Never play the motherhood card as an ace. Because it may turn out to be the dark joker.
Parenthood is, surely, relevant to a person's biographical details: any reference book giving a basic curriculum vitae leaves a category for "issue". Dynasties, even quite modest ones, have depended on "issue". Only a fool would ignore the significance of inheritance law, and in fiction, as well as in life, a rich childless aunt has wielded great power and influence because she could always threaten to leave her entire estate to the cats' home (and some have done).
Parenthood may be a factual element in a life: but it is no guarantor of virtue or a specific sense of responsibility about the future. Any social worker can relate appalling cases of feckless parents, cruel parents, abusive parents and parents who don't give a damn about the society in which their offspring would live.
Ah, but how about successful parents? How about those proud mums and dads who like to swank about how brilliant, rich, high-achieving and altogether remarkable their cherished offspring are? Maddening to others.
Parenthood can have an incentivising effect on some people - Andy Murray ascribed his most recent Wimbledon win to the birth of his baby daughter - but the outcome may be different for mothers and fathers. (Yes! Mothers and fathers are different! No equality law will ever make men and women identical.) Studies indicate that responsible men tend to work harder when they become fathers; but responsible women may reduce their focus on careers when they become mothers.
Critics could have claimed that Mrs Leadsom was a less suitable candidate to lead a government because her children were still at the stage of needing attention.
Being a mother can certainly make a woman more vulnerable to censure. Margaret Thatcher was criticised for being a bad mother, which was harsh: but how the children of a high-profile woman emerge will be the subject of public judgment.
A recent biography of Winston Churchill's wife, Clementine, draws the conclusion that she was an "unsuccessful" mother because two of her daughters made disastrous marriages, one killed herself after a career in alcoholism, and her son, Randolph, acted like a loathsome brat all his life. This, too, is a little hard: the Churchill genes were pretty loaded when it came to drink and self-destruction.
But to be a parent is to offer hostages to fortune. If we are frank, Theresa May is probably in a stronger public position because she is (to her regret) childless. There are no moody teenagers or restless twentysomethings to distract her from the task of extricating the UK from the EU.
I have often observed that some of the best teachers I have encountered have been childless, whether they were nuns or lay women.
They cared deeply about the future of their charges and hoped ardently for a better world in which the next generation might thrive.
Their care for "the long run" was altruistically transferred to a community, not merely invested in genetic issue.