It also showed that mothers who use handsets around their toddlers would cause the same difficulties.
The study has claimed that using a mobile phone regularly for more than ten years can also increase the risk of brain tumours.
Experts have warned that heavy usage can seriously affect male fertility.
According to the study, kids exposed to phones pre-natally and in early childhood show an 80 per cent rise in behaviour problems.
The study found that kids' brains absorb a greater proportion of radiation emitted by mobiles due to skull formation.
"We strongly recommend the Government actively discourages mobile phone use by children, including making public advice leaflets readily available in NHS waiting rooms," the Sun quoted Graham Philips, co-author of the study, as saying.
The study will be unveiled at the Radiation Research Trust Conference, in London.