The research findings are controversial

The way parents communicate with their children during the first year can have a far-reaching effect on both their language skills and intelligence, it has been claimed.

Speech and language therapist Dr Sally Ward, from the Speech, Language and Hearing Centre in London, has spent the last seven years investigating language development in babies and children.

Dr Sally Ward talks about her research

She believes the way parents talk to babies during the ages of nine to 13 months plays a pivotal role in their development, helping them to understand the sounds of words and their meaning.

IQ tests

Dr Ward's claims are based on a study of 140 nine-month-old babies. Half the parents were given advice on how best to talk to their babies, and the other half were left to their own devices.

Researchers went back to the children after seven years

Intelligence tests, carried out seven years later, found that nine of the children in the intervention group had IQs of more than 130, placing them in the "gifted" category. None of the children in the other group had such high IQs.

Dr Ward said: "The language skills of the intervention group were very significantly higher than the others.

"There was also an enormous difference in the general intelligence of the children in the intervention group, compared to the other children.

"And the average intelligence of the intervention group was a year and three months ahead of the other group."

Speech therapy programme

Dr Ward has developed a speech therapy programme, known as Wilstar, to put her theories into practice.

Some mothers were given advice on how to talk to baby

Toddlers across Manchester were recruited eight years ago for the Wilstar project.

Such was its success, children are still being offered the programme and many NHS therapists pay to be trained in the system.

Speech therapists visit the family for four months when the child is at a critical pre-language stage and show parents how to best develop speech skills.

Denise Ditchfield, of the Mancunian Community Trust, said: "A short period of time, working alongside the parents, building on their skills, has enabled us to bring that child or even take the child above what they would normally be achieving at 13 or 15 months."

Advice to parents

Dr Ward recommends the following advice to parents:

• In the early months, keep talking, even if the baby is not talking back.
• It will help to remove all the background noise which could distract the baby.
• Be on the baby's agenda and talk about what the baby is interested in.
• This all needs to be implemented for at least half an hour a day.

Experts have praised the way the Wilstar project improves children's language skills, but say claims that it improves intelligence itself, should be treated with extreme caution.

Dr James Law, a leading expert on speech therapy based at City University, London, said: "I'm wary of strong claims about improving intelligence - I'm reasonably happy with claims about improving language, speech and language - because speech and language don't necessarily correspond exactly to intelligence."

Scientific procedures

Experts say it is extremely difficult to measure intelligence in toddlers, and the methods Dr Ward chose to use have provoked doubts - children were not randomly assigned as in any normal scientific project.

Dr Sally Ward: "The first year is vital"

Dr Law said: "The children were assessed by the same people who'd been carrying out the clinical work. Now, in their writing, they say that this is a clinical necessity.

"Well, that may be the case, but it raises questions about how valid the results are."

James Birchinough was one of the original Wilstar babies. His IQ was tested last year, but his mother says he's perfectly ordinary - and has not turned into an egg head.