This giant study of more than 13,000 children found that using the handsets just two or three times a day was enough to raise the risk of babies developing hyperactivity and difficulties with conduct, emotions and relationships by the time they reached school age.
The study adds, the likelihood is even greater if the children themselves used the phones before the age of 7.
This research is said to have taken top scientists by surprise and will be published in the July issue of Epidemiology.
