The idea behind last night's contribution was, basically, that oldest children tend to be dominant - the Queen was offered as an example, as if driving ambition got her where she is today - while younger children tend to be rebels. A succession of older children agreed that they were far more disciplined than their weak-willed siblings; meanwhile, youngest children queued up to announce that they were bolder than their conformist big brothers and sisters. Middle children modestly admitted to being particularly balanced, caring people.
Frank Sulloway, author of the much-discussed book Born to Rebel, has tried to statistically analyse the difference birth order makes, and to explain it in Darwinian terms. Just as different species may occupy different ecological niches (one kind of finch eating seeds, another concentrating on nuts), so children find their own niche. He seemed to be confusing an analogy with an actual evolutionary mechanism here - I'm not at all clear how the effects of birth order could be inherited.
The commentary said, very reasonably, that birth order may have an effect, but it is a small and inconsistent one: our genes are more important. Kevin Leman, an American psychologist, scoffed at this. He thought that the idea of behaviour being genetically determined denies the freedom God gave us. For some reason, he didn't think this applied to the idea that birth order determines behaviour.
As trash psychology programmes go, this one wasn't too bad - it didn't go overboard to put one side of a controversial case, and it left room for nuances. But I'm baffled by this urge to explain the way people are, to make the whole world fit into a mould. It's the same urge that drives Starting Out (BBC1), the latest series from Laurence Marks and Maurice Gran, the comedy gods who gave us Birds of a Feather. Samantha, the heroine, has a boring boyfriend who wants to get married and settle down, and assumes that the little woman will chuck in her job and stay at home with "the kiddies". The notion that anybody under 30 could think this way, let alone use such a vocabulary, seems bizarre; but this seems to be a popular modern stereotype.
Samantha's best friend, Carly, is another stereotype: the blonde bimbo. She plans to have her navel pierced and a tattoo at the top of her thigh, and refuses to remove her high heels during a plane crash because they're brand new. Fortunately, the plane crash throws Samantha together with young Dean. Complimenting Samantha on her natural grace, Dean wonders whether she might be a ballet-dancer. His father, he says, used to work at Covent Garden - he was a greengrocer! How we laughed. There is no punchline, no situation here that doesn't conform to the audience's tiredest expectations. I'm flying a kite here - but do you think Gran and Marks were oldest children?