Sibling rivalry: It is thought that the children benefit fromthe age gap because parents have more time to invest in them
Forget expensive educational DVDs and private tutors, thesecret to smart children could be as simple as giving birth to themtwo years apart。
Researchers who studied thousands of children found a two-yeargap to be optimum in boosting brain power。
Any shorter, and the reading and maths skills of the olderchild dipped。
The effect was strongest between the first and second-born,but siblings in bigger families also benefited。
The theory comes from Kasey Buckles, an economist whose ownchildren are, rather fortunately, just over two years apart inage。
She said it is likely that the difference in academicachievement is linked to the time and resources parents can investin a child before a younger sibling arrives。
However, waiting more than two years did not increase theadvantage, the Journal of Human Resources will report。
Siblings with a two-year spacing include Albert Einstein andsister Maja, and Lord Attenborough and younger brother David。
Kasey Buckles, who lead the study told the Sunday Times: 'Webelieve this is the first time anyone has established a casualbenefit to increase the spacing between siblings.'
The study also showed that gaps between children in largerfamilies was also beneficial。
Buckles told the newspaper: 'The two year gap is significantbecause the early years are the most important in a child'sdevelopment so dividing your time when the child is one is moreharmful than dividing it when the child is already at school.'
The effect was more pronouncedin familieswith lower incomes, as those with more money could spend tocompromise for lack of time。