Another week, another nursery scare story. The latest news on pre-schoolers who have spent time being cared for outside the home goes for the jugular. A study of 3,400 American five-year-olds, conducted by the Temple University in Philadelphia, claims that childcare is not only damaging to the children who attend nursery - it also affects those children's future classmates in primary school.
The naughty nursery children's bad habits apparently rub off on the nice children brought up at home: "If your child has no childcare, but ended up in a [primary school] class where lots of children had childcare, your child ends up being more aggressive," said Professor Jay Belsky, who led the research. "There is a contagious effect." He calls this "direct peer contagion".
The idea that "nurseries are bad" is fast becoming accepted wisdom. Numerous recent studies have attempted to prove this hypothesis. Last year, a report from Oxford University concluded that children under three who spend more than 35 hours a week at nursery show "higher levels of antisocial behaviour and anxiety". A report by the National Institute of Child Health and Human Development (NICHD) in the US labelled nursery children "aggressive and antisocial".
These findings are reported unquestioningly because they tap into every working parent's worst fears. But these studies have already been called into doubt in the US, where critics argue that they are pure scaremongering.
During the early part of Belsky's research, one psychologist on the project, Sarah Friedman, said: "We have no way to attribute cause and effect. In the case of these findings, there is no way to attribute causality."
In other words, it is virtually impossible to ascertain why a certain child is misbehaving. Family circumstances will play a role; in addition, that particular child could have any number of undocumented mental, physical or emotional problems - long-term or just during the time they were observed. All these things have nothing to do with the childcare the infant has previously received. And in the case of the UK at least, the numbers don't add up.
The one common factor in all the studies is the "danger zone": the research always concludes that children who spend 30 hours or more in childcare are the ones most likely to have problems. But while there are 250,000 under-threes using nursery care in the UK, anecdotally the majority of these only attend three days a week or less. That's nowhere near 30 hours.
Many children included in this number attend for three hours a week so that their (non-working) mother can get her chores done. There are simply not enough children in this "problem group" (if it exists) to make this a real issue.
Last but not least, there is the question of how to evaluate behaviour.
Early researchers on the NICHD project said that the children's behaviour was within the normal parameters of aggression for their age group. And what did these monstrous, parent-deprived children - aged four and five - do in the latest study? They argued, fought, acted impulsively and disturbed classroom activities.
A five-year-old acting impulsively? Quick, call social services!