The genes you inherit from your parents have a say in how long you stay at school and whether you go on to university, according to the results of one of the world's largest genetic studies.
In findings that will further fuel the nature-nurture debate, more than 250 scientists working on the international project say they have identified 74 genetic variants which are linked to a person's educational outcome - namely the number of years of formal education completed.
Published in Nature this month, the genome-wide study established that on average a person who carried two copies of the genetic variant would complete nine more weeks of education over a lifetime, versus someone without a copy of a variant.
"It's the first study of its kind on this scale," said quantitative geneticist Peter Visscher from the University of Queensland's Queensland Brain Institute.
The study involved analysing the genetic material from almost 300,000 people of European descent, whose educational outcome was assessed at age 30 or above.
While Professor Visscher said the number of years of education attained was primarily dependent on environmental factors such as parenting, health and the quality of schooling, genetics accounted for between 20 and 40 per cent.
"For education, genetics should not be overplayed," he said. "But it can not be ignored either."
Intriguingly, the 74 genes found to be associated with educational outcome were also associated with a decreased risk of Alzheimer's disease and neuroticism. On the down side, they were also linked to a slight increase in psychiatric diseases such as bipolar and schizophrenia.
"These tiny genetic differences may ultimately help to understand why some people are more susceptible to early cognitive decline than others," he said.
There are 20,000 genes in the human genome - meaning the 74 genetic variants identified represent a tiny percentage. However Professor Visscher said he suspected they were the tip of the iceberg. He said as technology improved and the cost of sequencing came down, more would be revealed.
The cost of sequencing a human genome has already fallen dramatically. It now costs just $US1345 ($1860), compared with the $US95 million it cost in 2001 according to the US National Human Genome Research Institute.
"This study used a sample size of 300,000 people, which is pretty large but things are going to get even bigger," he said. "I suspect that within a few years from now there will probably be sample sizes of a million or so and I think we will be finding many hundreds of such genes."
The study was conducted by the Social Science Genetic Association Consortium, which involves hundreds of scientists from across the globe as well as Australians working at the University of Queensland and the University of South Australia.
