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Children are more likely to grow up to be involved in bullying if they go to a preschool with youngsters who are mainly from low-income families, new research reveals.

The report, released today, comes from a project that began in 1993 in which almost 500 children were tracked from age 5. This report covers their progress to age 16 but there are plans for a further report when the participants are aged 20.

The "Competent Children, Competent Learners" project found that the quality of teaching at age 5 still influenced children's reading and maths skills 11 years later.

The report indicated children whose mothers were highly educated did better academically at age 16.

Children who went to top preschools - where teachers responded to individual children's needs and frequently joined in activities - also outstripped their peers' achievements in their teenage years.

These results echoed those in reports released when the participants were aged 12 and 14.

New Zealand Council for Educational Research chief researcher Dr Cathy Wylie said the quality of the participants' early childhood education appeared to have an effect on whether they as teenagers experienced "social difficulties", such as bullying others or being bullied, bowing to negative peer pressure or mixing with children who got into trouble.

The report said 16-year-olds with the problems were more likely to have gone to a preschool serving mainly low-income families or families from a wide range of backgrounds.

A good-quality preschool education provided some protection.

Dr Wylie said facilities serving mainly middle-class families tended to provide greater exposure to print material, such as books and posters, and have more teachers asking open-ended questions.

"[This teaches children] about using language instead of hitting out," Dr Wylie said.

"You are getting more equipped, not just in terms of reading but also in terms of dealing with the world."

At age 5 and 6, the quality of early childhood education centres made just a small difference in students' maths and reading abilities, the study found.

The gap widened as the participants got older, with students who attended top preschools doing 14.5 per cent better at age 14. But that figure reduced to 8 per cent at age 16.

Education Minister Steve Maharey released the report. He said it reaffirmed the Government's commitment to its early childhood education plan, in which it pledged to offer 20 free hours for 3- and 4-year-olds at teacher-led centres.