“He shoots. He scores.” As Wayne Gretzky skates around the rink holding the Stanley Cup, fans go wild. You can feel the rush, the excitement, and the joy. All because of dopamine, a chemical that gives us feelings of pleasure and reward.

Of pleasure and reward

Dopamine plays many roles in our brain, from memory, to attention, to cognition. This versatility also makes it dangerous. Even small changes in dopamine levels can cause serious mental disorders, including schizophrenia and Parkinson’s disease.

Dopamine is also linked to self-control, risk-taking, novelty seeking, addiction, mood disorders and even happiness. The latest addition to this list is sexual behavior, to be more specific – promiscuity and infidelity.

People with certain changes in one of the dopamine receptor genes, DRD4, are more likely to be promiscuous and cheat on their partners.

The DRD4 gene

The DRD4 gene encodes the dopamine receptor D4. While one class of dopamine receptors, called ‘D1-like’ receptors, turns a series of genes on, the D4 receptor belongs to the ‘D2-like’ class that turns these same genes off.

People with schizophrenia have an imbalance between the D1 and D2 receptors. They have more D2 receptors than normal and this may be the cause of the main characteristic associated with schizophrenia – unusual social behavior.

Disrupting the balance between D1 and D2 receptors can also have other serious health implications. For example, there is a link between lower levels of D2 receptors and Parkinson’s disease.

On top of this, attention deficit hyperactivity disorder, novelty seeking and now, sexual promiscuity and infidelity are all linked to genetic changes within the DRD4 gene.

The “promiscuity” variant 

All of these behavioral changes are related to a section of the DRD4 gene that is repeated between two and eleven times.

In one study researchers looked at sexual behavior and intimate relationships in young adults and found that people with at least one DRD4 allele containing 7 or more repeats (7R+) were twice as likely to be promiscuous.

Almost 45% of people with a 7R+ allele reported to have had a one night stand, compared to only 24% of people with less than seven repeats. There was no significant difference between the two groups when it came to cheating on their partners. 

But, people with a 7R+ allele had more extra-pair partners, i.e. they cheated with multiple people, which is why the longer repeat versions of the DRD4 gene is dubbed the ‘promiscuity’ gene.

Risky business

One explanation to these findings brings us back to dopamine levels. The 7R+ version of DRD4 does not bind dopamine as effectively. This means people with this version need higher levels of dopamine to feel pleasure.

It’s possible that these people are just trying to boost their dopamine levels with their risk-taking, novelty-seeking behaviour and more sex. However, while risk-taking and novelty seeking may be socially acceptable excuses, promiscuity certainly isn’t.

Genetically pre-programmed

So, if people are indeed genetically programmed to be promiscuous, can we really label this behavior as ‘cheating’? Before we can answer this, we need to answer a much bigger question: how much are we really defined by our genes?

We will soon be entering a future where it will be possible to know our entire genetic makeup. How we choose to use this information, whether it is to modify behaviors, or to excuse our unsavoury habits, remains entirely up to us. Just remember, whether you like it or not, the choices we make today will have a huge impact on our society and future generations.

Does your DNA make you more likely to be unfaithful? Find out with the Promiscuity Gene DRD4 Test.

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