How to Be a Better Dater (HTR2A)

In a 2016 study conducted on Asian Americans, a team of researchers looked at speed-dating success by participants and their genetics (R).

The study looked at people who were a ‘match’ i.e. they both agreed to go on a second date. The researchers discovered variations in 2 different genes that were previously linked to social dynamics (R).

In these meet-ups, participants only had 3 minutes to decide whether or not to go on a second date (R).

This study highlights the role of the serotonin and opioid systems in mate attractiveness (R).

The study suggests that this genetic effect could extend beyond romantic attraction to other social situations (job interviews, etc…) (R).

Serotonin-related genes may play a role in dating success and social skills.

The study found that participants who were more likely to be asked on a second date (both men and women) had genes that corresponded to personal traits that people often desire in a romantic partner – such as social dominance & leadership in men, and social sensitivity & submissiveness in women (R).

In other words, men and women with genes consistent with gender stereotypes were more likely to receive second date offers. They were also seen as more desirable romantic partners (R).

For example, submissiveness and social sensitivity, stereotypically female traits, predicted greater speed-dating success for women, whereas the leadership/social dominance, stereotypically male traits, predicted greater speed dating success for men (R).

It is important to remember that this was just one study of only Asian Americans and these findings might not translate to different cultures or under different testing conditions. That being said, they certainly are interesting and informative. 

Men had better speed dating success when they exhibited stereotypical ‘male traits’ such as social dominance and leadership. Women were more successful in speed dating when they exhibited these stereotypical ‘female traits’ such as social sensitivity.

When it came to the serotonin gene (HTR2A), men who carried a certain variation were rated as more desirable potential mates and were more likely to receive second date offers. In contrast, women who carried the same variation as men were more likely to be given the cold shoulder by men (R).

The “C” allele of rs6311 of the HTR2A gene has been linked to leadership/social dominance and predicted greater speed-dating success for men.

One prior study found that young men with the “C” allele of rs6311 were rated as more popular by their same-gender peers after 45- to 60-min group interactions (R).

The C-allele was characterized by studies as a “secret ingredient” for popularity among peers (R).

Carrying the C-allele enhanced the relationship between aggression and popularity, particularly for those boys who have many female friends [R].

This variant (C allele) seems to have an “enhancer” effect, whereby if you already have characteristics that make you popular, this variant will make those characteristics more noticeable. However, the C-allele by itself had no effect on popularity [R].

The ”T” allele was associated with an increased risk for Chronic fatigue syndrome (CFS) [R] and irritable bowel syndrome [R].

So if you’re tired, have gut problems and you’re bad with women, you should start thinking about the possible role your genes might play in this, and how you can combat these effects. 

On the downside, people with the “CC” variation reported more anger and aggression-related behaviors [R].

The serotonin receptor gene (HTR2A) is the same receptor that is altered by both psychedelics (such as LSD) and SSRIs (R).

Your Serotonin SNP for Dating & Popularity

In men, for the SNP rs6311:
C = better speed dater (opposite for women). More aggressive and socially dominant.
T = worse speed dater (opposite for women). Less aggressive and socially dominant.

When it comes to speed dating, the study grouped the CT/CC genotypes together and compared it to TT, so it’s unclear from this specific study what effect the CT genotype would have vs CC. However, having one T allele has an effect on gene expression, and in other traits studied there were additive effects with each T allele, so presumably, each T allele you have could result in stronger effects on dating success. But without further study, this is just a conjecture. 

Mechanism

Each “C” allele of rs6311 is shown to be associated with lower 5HT2A protein gene expression than the “T” allele (R).

Several studies have shown that the serotonin system contributes to the formation of social hierarchy.

Monkeys

In adult male monkeys, researchers found that serotonin levels depended on the social rank of a monkey, such that dominant monkeys had approximately twice the serotonin concentrations of subordinate monkeys (R).

Interestingly, when a dominant monkey was temporarily isolated, its serotonin levels diminished to approximately the same level as those of the subordinate monkeys within 1 day. When these dominant monkeys were placed back into group housing, their serotonin levels increased (R).

On the other hand, the transition from a subordinate to a dominant position in the social hierarchy was accompanied by an increase in serotonin levels. It’s important to note that brain levels of serotonin were not measured, which is a critical piece of information (R).

Another study examined whether increasing serotonin levels promoted social dominance in adult male monkeys (R).

After the removal of the most dominant monkey from a group, certain subordinate monkeys were administered either tryptophan to increase serotonin levels, or an SSRI (fluoxetine) for 4 weeks (R).

Compared with the non-treated controls in their group, subordinate monkeys who were treated with either tryptophan or the SSRI exhibited greater levels of dominance within 4 weeks (R).

Conversely, when the subordinate monkeys were administered a drug that disrupts serotonin function or a 5-HT2A-receptor blocker, the monkeys that received treatment forfeited their dominance and submitted to the non-treated controls within the group (R).

In addition, the size of the brain where serotonin is very active (raphe nucleus) is larger in dominant monkeys than insubordinate monkeys. Although the study did not directly measure 5-HT levels in the brain, this observation is consistent with the idea that the 5-HT system influences the formation and maintenance of a social hierarchy (R).

Higher serotonin levels seem to cause monkeys to be more dominant and increase their social rank.

Humans

Administration of serotonin to humans has a similar effect on social dominance as it does with monkeys (R). 

Healthy human participants received a dose of tryptophan (3 g/day) with their meals for 12 days and were asked to verbally describe their own communication frequency, agreeableness, and dominance (R). 

The participants who had been administered tryptophan exhibited an increase in dominant behavior and a decrease in quarrelsome behavior (critical comments of others) (R). 

Higher serotonin levels seem to cause humans to be more dominant, expressive and agreeable.