Sex-Ratio - Article

Nature tends to make sure that there is an equal amount of boys and girls being born, but what happens when this is not the case? What impact will an unequal ratio of men and women have on our behavior and preferences? A deviation from an equal sex-ratio is a relatively new development and can be seen in for example china, where there are relatively more men than women. China is thus male-biased. This will have various societal and even economical consequences, especially when this unequal distribution of gender is prevalent in males and females of a reproductive age. We call this an operational sex ratio, when the imbalance may have potential reproductive consequences.

Previous research has shown that the ratio of men and women, will have an effect on how much effort is put into mating effort such as within-gender competition and courtship. Thus males are expected to put more effort into mating strategies when there are relatively less females and display more competitive behavior. When men and women are already in a committed relationship, and there seems to be less opposite sex partners to choose from, they report being happier and more committed to their current partner. When on the other hand, individuals feel as though there are other alternatives for their current partner, they take various preventative measures to ensure their partner will not leave them. When men perceive a male-biased ratio, they become more clingy, aggressive and intrusive in their partners lives. When women perceive a female-biased ratio, they become less intrusive giving their partner more freedom. Under such conditions, women may perceive their partners as being more valuable, more attractive and suitable as mating partners than they would do otherwise.

Societal and financial consequences of a biased sex ratio

A biased sex ratio has been shown to have an impact on men’s financial behavior. Men have been found to invest more and save less, when a presented with a male-biased condition. The high investments were especially prevalent when investing in current relationships, such as valentine’s day gifts and engagement rings. This is most likely related to high intra sexual competition that we discussed previously. Women perceive men with higher resources to be more powerful, thus such behavior could potentially help males to be successful with their potential partners. This finding could also have serious societal consequences. If men are much more likely to invest and be less cautious with their savings when presented with a male-biased environment, their financial choices may have long term consequences. Let’s consider China for instance, where there are significantly more males than females. If males are more likely to display risky financial behavior, the government may have to adapt new strategies to counter the consequences of high loans and impulsive expenditures. Luckily, this behavior depends merely on perception, so managers and governments could use various sex-ratio cues to shift male perceptions of gender ratios in order to avoid negative consequences.

Perceptions of gender ratio may also have an impact on our career investments. Research has shown that when women perceive a female biased environment, women will prioritize their career over family. When presented with a male-biased environment, more women strive to start a family rather than focus on their careers. When men perceive a male-dominated environment, they seem to strive invest more in their careers in order to strengthen their position in the intra-sexual competition for the relatively fewer females available.

Religion may also play a role since as high perceived competition seems to strengthen religious values and support make individuals more prone to acknowledge more tradition social norms. This is due to the perceived threat of high competition; individuals strive to acquire a monogamous relationship with high commitment.

There are apparent differences between women and men who perceive high intra-sexual competition; however there may also be individual differences in coping strategies with regards to a gender biased ratio. These differences will then depend on the individuals mating value and the environmental conditions.

Mating value and career choices

As stated above, our perceived mating value may effect how we deal with high competition This is because individuals with a high mating value are more desirable and more likely to attract higher value mates of the opposite gender. We already mentioned how career may be influenced by gender biases, now we will extend this further and consider how this may be affected when taking into consideration individuals perceived mate value. When men perceive their mate value to be high, they seem to desire more prestigious careers under male-biased sex ratio circumstances. On the other hand, women with a high-perceived mate value seek more stable occupations (teacher, nurse etc..) under a female-biased sex ratio environment. We could thus conclude that while highly desirable men strive to have a higher social status and a means to provide for their mate, highly desirable women can rely on their dominant high status male partners, while settling for a more stable occupation.

Hormonal behavior

We will be considering the following three hormones: testosterone (T), cortisol (C ) and Estradiol (E). Individuals high on testosterone are more likely to exhibit aggressive behavior as testosterone is linked to higher aggression, dominance and social status. Individuals, who are in serious relationships, often have suppressed T values, as they have to compromise their dominance. When experiencing a decrease in social status, individuals high on T will experience an increase in C, but this is only temporary and will increase once their social status loss is averted. People high in T strive for status and are relieved once they have achieved it and function well. People low on T are less sensitive to loss, but feel uncomfortable in higher social status positions. This could be due to the fact, that they may not be dominant enough to be able to cope with a high status position and thus feel underachieved when put in such a position. For women, E has a similar function to T in men. Women’s E values fluctuate in accordance with their current status. Women who have more E, are attracted to men with higher T. There seems to be a positive correlation between a women’s E values and the mating efforts she exhibits.

Finally individuals with high C values tend to display more anxiety and defensive behavior. Individuals high on C tend to be less aggressive and reactive in social situations. Thus C plays an inhibitory role in social behavior as individuals high on C tend not to engage in risky social situations. Lower levels of C are associated with more of a social approach. Individuals who are high on T and low on C tend to be the most aggressive and socially engaged.

Work for WorldSupporter


JoHo can really use your help!  Check out the various student jobs here that match your studies, improve your competencies, strengthen your CV and contribute to a more tolerant world

Working for JoHo as a student in Leyden

Parttime werken voor JoHo


Check how to use summaries on

Online access to all summaries, study notes en practice exams

Using and finding summaries, study notes en practice exams on JoHo WorldSupporter

There are several ways to navigate the large amount of summaries, study notes en practice exams on JoHo WorldSupporter.

  1. Starting Pages: for some fields of study and some university curricula editors have created (start) magazines where customised selections of summaries are put together to smoothen navigation. When you have found a magazine of your likings, add that page to your favorites so you can easily go to that starting point directly from your profile during future visits. Below you will find some start magazines per field of study
  2. Use the menu above every page to go to one of the main starting pages
  3. Tags & Taxonomy: gives you insight in the amount of summaries that are tagged by authors on specific subjects. This type of navigation can help find summaries that you could have missed when just using the search tools. Tags are organised per field of study and per study institution. Note: not all content is tagged thoroughly, so when this approach doesn't give the results you were looking for, please check the search tool as back up
  4. Follow authors or (study) organizations: by following individual users, authors and your study organizations you are likely to discover more relevant study materials.
  5. Search tool : 'quick & dirty'- not very elegant but the fastest way to find a specific summary of a book or study assistance with a specific course or subject. The search tool is also available at the bottom of most pages

Do you want to share your summaries with JoHo WorldSupporter and its visitors?

Quicklinks to fields of study (main tags and taxonomy terms)

Field of study

Comments, Compliments & Kudos:

Add new contribution

This question is for testing whether or not you are a human visitor and to prevent automated spam submissions.
Enter the characters shown in the image.
Access level of this page
  • Public
  • WorldSupporters only
  • JoHo members
  • Private