Fact or Myth: Are Reproductive Milestones Determined by Genes?

This is FACT.

In part, at least. A recent study shows that while nurture—your environment, upbringing, social network, etc.—plays a large role in shaping reproductive milestones such as when you lose your virginity and when, and how many, children you will have, nature—your genetic coding—is also a significant determinant. According to John Perry, a geneticist at the MRC Epidemiology Unit at the University of Cambridge, “There are core biological pathways underpinning what we believe is mostly societal and cultural.” In other words, your reproductive decisions are not all about choice.

How Much Is Nature?  sexual attraction

For the study, published November 2015 in Nature Genetics, researchers examined 125,000 people’s genes using personal information stored in the UK Bio Bank, a national health resource that contains the blood, urine, saliva samples, and lifestyle data of approximately 500,000 men and women between 40 and 69 years of age.

Scientists examined genes for any associations with reproductive milestones…and found many! Results showed that genetics (nature) influenced reproductive milestones by 25% and nurture (environment and upbringing) accounted for the other 75%. There were precisely 38 gene regions that impacted significant reproductive choices. And while genes aren’t directly responsible for when you’ll have sex for the first time or how many children you will have, they do exert an influence that deserves acknowledgement.

For instance, the earlier one goes through puberty, the more likely he/she is to have sex at an earlier age, as well as having more kids in the long run. And researchers discovered that the gene CADM2, which is associated with greater risk taking, is also linked to procreating more often. And the MSRA gene, which carries a correlation with irritability, was linked to losing one’s virginity at an older age.

Why Should We Care?

There tends to be judgment around reproductive choices, such as when you lose your virginity or if and how many kids you have. Understanding that genes are involved in these choices can help remove some of this judgment, so that we are more accepting of our own choices and the sexual journeys of others.

As the field of epigenetics grows, scientists are understanding the true nature of genes, and how we can use them to help bring out the best in our health choices while honoring our individual nature and tendencies. The study makes sense in light of other genetic studies, such as a separate 2015 study published in Nature Genetics. The study analyzed over half a century of data on 14.5 million pairs of twins and discovered that when it comes to the influence of nature vs. nurture, it’s a decidedly 50/50 split.