We've all heard the saying "once a cheater always a cheater", but according to the team at AsapScience, this commonly used expression may have "a basis in reality".
Dopamine - sometimes called "the happy hormone" - is released when we engage in pleasurable activities, such as eating food and having sex.
Everyone has a dopamine receptor, but the gene comes in two forms - some people have the long allele variant while others have the short allele variant.
According to the video, one US study found that 50% of people with the long allele variant of the gene had cheated on a partner, compared to just 22% of people who had the short allele variant of the gene.
People with the long allele gene were also found to be more likely to take risks and succumb to addictive behaviours when compared to their short gene counterparts.
Additionally, levels of the hormone vasopressin - similar to oxytocin which is known as the "cuddle hormone" - may also play a role in infidelity.
Vasopressin levels have been shown to affect feelings of trust, empathy and social bonding, so the hormone may have an impact on our relationships.