Upbringing, religion and how early puberty sets in have all been shown to influence the age of sexual debut. In a novel study, researchers have identified for the first time the heritable components that influence how early or how late people lose their virginity. Remarkably, heritability accounts for about 25 percent. In other words, all other things like "nurture" being equal, some people are primed to start their sexual life earlier than others.
The Cambridge University team analysed the genes of 125,000 people aged 40 to 69 from the U.K. BioBank project. The most common age for both women and men losing their virginity was 18.
Researchers identified 38 gene regions that affect the age of first sex among them those that regulate the release of sex hormones and the age of puberty. Early puberty teenagers who start having sex earlier than others is, in itself, not surprising. But other genes were found to alter personality and behaviour, and these were far more interesting. For instance, one gene variant called CADM2 is linked both to risk taking behaviour and early sex age. In the opposite spectrum, a gene variant called MSRA is linked to irritability and older virgins.
Later, the researchers show that early puberty has a direct, albeit small, effect on the age women lose their virginity and birth their first child. Both early sex and birth are linked to poorer education and lower earnings later in life, the researchers report in Nature Genetics.
“This is an interesting study where using genetics one can better untangle cause and consequence of a complex human behaviour. Genetics only contributes a small part to age of first sexual intercourse, but the very random nature of each person’s genome means it can be used to trace the impact of this behaviour into later life with less concern about complex correlations confusing cause and consequence," Ewan Birney, co-director of the European Bioinformatics Institute near Cambridge, told The Guardian.
“This study really shows the benefit of the size and comprehensive, detailed measurement by the UK BioBank, the world’s largest medical cohort. We can expect many more results with a similar approach in the future as researchers mine this resource," he added.