Sending your child to a private school makes no difference to his or her cognitive development, according to a new study by the University of Queensland.

What will make a difference is the education level of both parents, as well as the amount of time a mother spends with her child.

The study, entitled Does school type affect cognitive and non-cognitive development in children? began in 1999, and follows 4,000 primary school-aged children in years three to five.

• Why Australia shouldn’t fund private schools
• Public vs private school: why it doesn’t matter

“Our results show that sending children to Catholic or other independent schools has no significant effect,” said Professor Luke Connelly, who co-authored the study with Dr Hong Son Nghiem.

“Any differences we see in test results are not due to the school type. Rather, they reflect the differences between households and students that already exist in society.”

He said the findings support studies carried out in “three different continents” that also suggest there is no difference between public and private schools.

Controversially, the study found that the more a mother works, the lower the child’s test score. Fathers’ working hours, meanwhile, made no difference.

Children of parents who had both completed Year 12 had significantly higher test scores on all subjects.

Children that identified as Aboriginal and Torres Strait Islander on scored lower in grade three, but by grade five their scores had improved.

Low birth weight also corresponded to lower test scores.