A survey of 1,340 students in the final two years of secondary school surprised the researchers. Dr John Condon, an associate professor of psychiatry at Flinders University in Adelaide, called the adolescent perceptions worrying and said he had not expected to find such idealism.

More than a quarter of girls become pregnant between the ages of 13 and 19, with about half seeking an abortion. Less than 2 per cent choose adoption. The survey asked students about their attitudes to childbirth and parenthood. Two out of three thought that a couple became closer during pregnancy, and boys had even rosier views than the girls.

A third of the students believed that having children would improve a relationship while a slightly higher proportion were convinced that competent parenting came naturally.

Two per cent of those surveyed said they had obtained their knowledge about sex and conception at school. About half had learned what they knew from family and friends and 37 per cent said childbirth and parenting were basically common sense.

Dr Condon said the results suggested something was wrong with what was being taught in schools. “Sex education concentrates on the biological side of things without giving insights into what it really means to be pregnant, and then become parents.”

Neither the type of school students attended, whether private or government, nor their social class or religion had much influence on their beliefs and attitudes.

Boys at all-male schools appeared to have significantly more idealised and traditional views than students from co-educational schools. Girls from single-sex schools were found to be the most realistic.