Who doesn't shout at their children? OK, so you might not do it in front of your friends (we all know it's bad), but rare is the parent who manages to keep cool, calm and collected at all times, only ever speaking in measured tones.
It will come as unwelcome news, then, that research shows it's more damaging to children than most people realise. One study by psychiatrists at Harvard Medical School found it can significantly and permanently alter the structure of their brains.
Another study by psychologists at Plymouth University in Devon found that those who raise their voices at youngsters expose them to the risk of developing cancer, heart disease and asthma. Even minor shouting causes children stress, found the researchers, which in turn can cause biological changes.
There's an American saying that shouting at your children to obey is like using the horn to steer your car – and it produces the same results.
"When a child is being shouted at, they do not hear what is being said to them," confirms Michael Duke, principal educational psychologist at Denbighshire County Council.
"One child summed it up when he talked about a teacher that shouted at him: 'I didn't hear what he said, I only heard the noise.' It's a waste of energy for all those involved."
Rachel Calum, professor of child and family psychology at the University of Manchester, agrees. "Shouting can frighten children and put them in such a state of heightened arousal that they can't concentrate on the message given. It also increases the chance of the child having a hostile reaction and shouting back."
Her damning verdict is that at its most extreme, shouting is emotional abuse.
Some years back, Hollywood star Jennifer Aniston announced she wasn't even on speaking terms with her mother partly because she shouted at her when she was a child.
Oh dear. Losing your rag and yelling isn't something that most parents are proud of, but the majority do it at least sometimes. Triggers include exhaustion, having a bad day or feeling disappointed that you haven't raised kids quite as well behaved as you'd aimed for.
Mother-of-three Robyn Howarth says feeling unsupported can also prompt shouting. "If I'm on my own for a day with the kids, I'm much more likely to shout than if someone is helping me out or just providing some adult company."
Meanwhile, mother-of-two Helen Taylor says: "Most often for me, it's the stress of trying to get them out of the door for school or into the bath or to brush their teeth – basically, the things that happen every day in the same way and have to happen by a certain time or everything else goes wrong. The shouting comes after asking politely two, three or four times and still no result."
Parents often shout because that's how they were raised themselves, adds Sarah Ockwell-Smith, director of ToddlerCalm. "If you were raised in an authoritarian household and attended a school where shouting teachers were the norm, it often transpires that you will slip into the same habits."
"I feel so ashamed afterwards," says mother-of-two Louisa Cape. "I promise myself I won't do it again because there are obviously better ways of getting things done. But then I do and the fact is that the more you shout, the less they listen, so the louder you find yourself shouting. It's horrible."
Suzie Hayman, spokeswoman for Familv Lives and author of Teach Yourself How to Have a Happy Family Life, reassures parents that it's unrealistic to never shout. Family life is stressful and emotional and most intimate relationships involve rowing sometimes, she explains.
But there are degrees of shouting, she says. Some parents practically roar at their kids, whilst some parents are prone to use shouting to label the child ("You little brat") not the behaviour ("Hitting your sister was a bad thing to do") – both of which are particularly destructive.
Some families are a lot more "shouty" than others, she adds. "Certainly, if it's persistent and it's the way you mainly communicate with your child, then it's as abusive as hitting a child.
"But if you mainly have fun and chat with your children, but you have the occasional meltdown, I honestly don't think it matters."
Look at the number of times you praise versus the number of times you shout, she advises. "Make sure the balance is at least 3 to 1 and make a conscious effort to say lots of pleases and thank yous and reward good behaviour so that the main atmosphere in the family is positive."
Think about the trigger situations, adds Naomi Richards, author of The Parent's Toolkit and speaker at The Mum's Show Live. Does it always happen at a particular time of day? Would it help to give yourself more time in the mornings?
"Keep in check what you are feeling," she adds. "If you feel stressed, tell yourself it's your stress and that your children don't need to feel it."
Think about how you would feel if someone spoke to you like that, adds Ockwell-Smith. "And if you feel yourself needing to shout, I often recommend 'time out' – but for the parent, not the child. This can be physical, so you take yourself out of the room for a minute or two whilst you calm down (breathing in to 7 and out to 11 through your nose is good for this) or just take some psychological time out, almost mentally stepping back from the situation whilst you collect your thoughts."
Initially, this can be quite hard, especially if your first line of defence is to shout, she says. "But it's amazing how quickly children respond to a calmer, more respectful home life when the shouting is removed. I would say it takes as little as a fortnight to make a significant change."
Keeping your child more engaged can help too, believes Calum. "A busy, occupied and contented child is much less likely to cause you situations in which you feel the need to shout."
There is always the argument that children who have never been shouted at can find themselves hypersensitive in the real world and most shouters agree that a good yell can clear the air.
It's not that anyone would promote shouting, of course, but let's face it – being calm all the time as a parent is a myth and surely there has to be some silver lining.
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