A top parenting expert has warned mothers that being too possessive of their sons and not letting men be strong father figures can be detrimental to their boys' upbringing.

The frank advice comes from parenting expert Noël Janis-Norton in her new book Calmer, Easier, Happier Boys.

According to the parenting and behavioural specialist and former teacher, fathers have much greater influence than mothers in shaping boys into well-adjusted young men - but too often mothers find it hard to back off and let dad take control.

A top parenting expert has warned mothers that being too possessive over their sons and not allowing fathers to get enough of a look can be detrimental

'Without a strong father-figure, (which could also be a step-father or grandfather), boys may struggle to learn how to express their emotions constructively, how to handle their physical strength and learn to respect others - and themselves,' Janis-Norton tells the MailOnline.

‘Mothers need to allow dads to be dads and to have their own relationship with their children - and in particular with their boys - without trying to micromanage,' she says.

The parenting expert, who has been credited by the likes of Helena Bonham-Carter turning her family life around, also warns mothers about being barking too many orders.

'A boy will lose respect for the mother who appears to bossing the father around – or criticising him,' she says.

So when Dad gets little Tommy dressed in the wrong clothes, feeds him the wrong breakfast and then starts a pillow fight should Mum just look on through gritted teeth?

'Yes - absolutely she should!' says Janis-Norton. 'And the gritted teeth part comes because mums assume they know best - but actually none of us is perfect. We’ve got weaknesses too.

'We’re not doing it right all the time. So really we shouldn’t be judging the dads!'

Despite the title of her book, the Calmer, Easier, Happier Boys author, is at pains to point out that keeping calm is not always the goal. In fact, she actively encourages play-fighting for boys

Of course mums are usually more familiar with the routines: 'Even in families where both parents work long hours outside the home, children tend to spend more time with their mothers,' says Janis-Norton.

'That’s not a problem for a girl – but for a boy it is. Because the genetically preprogrammed urge is for boys to copy their fathers. And it’s hard for a boy to do that when he doesn’t spend enough time with Dad.'

Despite the title of her book, the Calmer, Easier, Happier Boys author, is at pains to point out that keeping calm is not always the goal. In fact, she actively encourages play-fighting for boys - especially when it's with their father.

'Mums generally don’t have an interest in play fighting and they worry someone's going to get hurt, or feelings will get hurt, or clothes will get ripped or something will get damaged.

'But none of that is as important as boys getting their energy out and through play fighting they learn a lot about how to fight fair.

'They learn how to control themselves, they learn how not to be too rough - and they also learn how to make amends if it does go too far.'

By play fighting with Dad, boys can learn how to control themselves, how not to be too rough - and how to make amends if they have been too rough

'Dads can teach boys all of that,' she says but does advise that play fighting that is likely to become manic or annoy others in the house is best taken outside.

Of course mothers are not the only ones that need to make an effort to encourage that father-son relationship to flourish. Fathers needs to work at it too:

'Because so many fathers are spending more hours at work and often have longer commutes their time at home may be taken up with household chores such as paying bills, mowing the lawn and doing repairs.

Noël Janis-Norton has written the new book using her tried-and-tested Calmer, Easier, Happier Parenting strategies

'You can see that even a loving, conscientious father can end up not being a very good role-model.

'They may be reluctant to insist on good behaviour, to enforce rules and routines and to follow-through when rules are broken or routines drift.

'The less involved a father is, the less confident he will feel and the less confident he feels, the less involved he will want to be,' she warns.

Janis-Norton decided to write the book, which adapts her tried and tested Calmer, Easier, Happier Parenting strategies to focus on boy behaviour, after parents of boys kept asking the same questions.

'They were often frustrated exasperated and perplexed,' she says. 'Parents often complain that their boys are fidgety and easily distracted and socially immature. Parents worry that their son isn’t fulfilling his academic potential.

'Another issue that concerns parents of boys is the tendency towards disrespect, defiance and aggression. And parents don’t know what to do.'

The most important piece of advice Janis-Norton has for parents is to sop telling their children off.

It may not sound like a recipe for cooperative offspring, but according to Janis-Norton it is key: 'Telling off doesn’t work and motivate to improve,' she says.

'Thankfully there are strategies that can help parents get back in charge,' she says.

‘The strategies I teach parents will help boys to become more cooperative, more confident, more motivated, more self-reliant and more considerate.'

One such strategy is Descriptive Praise, describing what your child is doing right rather than what they're doing wrong.

‘Let’s imagine a family around the dinner table. The little girl is eating with her knife and fork properly and using her napkin properly and sitting with legs in front of her – and waiting to swallow her food before she talks.

'The boy is doing all the opposite - plus he’s singing and talking too loudly and interrupting and maybe doing a deliberate burp.

Noël Janis-Norton's new book: Calmer, Easier, Happier Boys

'So it’s very tempting to keep saying "no", "don’t", "stop".'

'Reprimands may - or may not - get you immediate cooperation, but in the long-term telling off and endless reminders make the behaviour worse – because when children keep hearing about what they’re doing wrong, they start to feel that’s who they are.

'So after a while they don’t even bother trying to improve their behaviour.

'In fact, boys often enjoy being able to wind up their parents by burping or making some kid of a vulgar joke.

'So I advise parents to focus most of their attention on the OK things that the boy is doing. Notice and mention the tiny steps in the right direction.

'I’m not saying it’s easy to stay positive; it takes a lot of self-control. But it’s worth practising this strategy, which is called Descriptive Praise, because the more we notice when our children are doing things right, the more motivated they will be to behave better.'

Within a meal a parent might say: ‘You’re sitting up straight’ or ‘You’re using your napkin instead of your sleeve’ or even 'Your chewing with your mouth closed and I cant see any of the food in your mouth’.

'If you take a moment to look carefully, there’s always something your son is doing that’s OK that you can comment on,' Janis-Norton says.

'For example, if your son is talking too loudly, just look at him, with a friendly face, and wait a few seconds until he pauses. Then at that moment you can say, with a big smile, "And now you’re not talking too loudly. You’re using your indoor voice".'

Helena Bonham-Carter, who took a course in Calmer, Easier, Happier Parenting in 2010 is just one mother who has been helped by Janis-Norton's strategies.