Gender vs. Sex: What Is the Difference?

How Identification Impacts Your Health

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In the past, the terms gender and sex were used interchangeably. Both words pointed to the fact that all people can be described as either a male or a female. Most people didn’t really question this. Fast forward to the present—the concept of only two genders is an outdated and inaccurate representation.

Today, there is a distinct difference between the designation of gender vs. sex. To get up to speed on today’s lingo when it comes to these terms, one must understand the difference between sex and gender, as well as comprehend some of the commonly related terms including gender roles, gender identity, and gender expression.


According to the Merriam-Webster dictionary, the definition of sex is “either of the two major forms of individuals that occur in many species and that are distinguished respectively as female or male, especially on the basis of their reproductive organs and structures.” 

Essentially, sex is described by the dictionary as the genetic and biological differences in the male versus the female species—such as the difference in reproductive organs.

Hormonal Influence

The genitalia in the male and female are different, as too are the hormones produced by the sex organs—primarily estrogen, progesterone, and testosterone. Testosterone, estrogen, and progesterone are present in men and women but occur at different levels. Men, for example, have a much higher level of testosterone and a much lower level of progesterone and estrogen than women.

Chromosomal Influence

In additional to hormonal influences, there are other genetic factors that biologically impact the sex of a person. For example, women have 46 chromosomes including two X chromosomes. Men also have 46 chromosomes but have an X and a Y chromosome. The Y chromosome carries the signal that results in the growth of the embryo’s testes. 

In humans, the sex is determined by the presence of the Y chromosome; however, there are a few exceptions to this occurrence. As the testicles are developed, this leads to the production of testosterone, which, in turn, impacts many of the body’s tissues in the early development of a male. 

People with one X and one Y chromosome are typically considered the male sex, while those who have just the X chromosomes are usually female.


Gender, on the other hand, has become a bit more of a complicated term.  Gender can refer to either of the two sexes (male or female), both sexes, or neither. 

Gender pertains to a social or cultural difference, rather than a biological one.

The term gender (as compared to the term sex) can be used in broader terms to describe a wide range of personal identities that are not associated with male or female roles. It includes how individuals see themselves (gender identity), how others perceive them and expect them to behave (gender norms), as well as the interactions (gender relations) that they have with others.

In a 2017 CBS News article, gender was described as “an extremely personal part of who we are, and how we perceive and express ourselves in the world. It is a separate issue entirely from sex, our biological makeup, or sexual orientation (who we are attracted to).”

There is terminology that helps us describe the "layered world of gender,” says CBS News. People can identify as a host of different genders.

Gender Identity

Gender identity is a person’s self-concept as a female, male, a combination of both female and male, or neither. The gender identity of a person can be the same as one’s biologically assigned sex at birth—but it doesn’t necessarily have to be.

A person’s biologically assigned sex may not line up with their gender identity. Those who do not identify with the assigned sex may describe themselves as:

  • transgender: a broad term that refers to anyone who claims a gender identity that is different from cultural or societal expectations (those that are based on the sex assigned at birth)
  • non-binary: a gender that falls outside of the binary system (binary means relating two things); the male/female genetic difference may be viewed as binary, but this is not always the case (for example, some men are born with two X chromosomes and some women are born with a Y chromosome); non-binary simply means not identifying as one of two sexes.
  • gender-nonconforming: an umbrella term referring to those whose gender expression does not conform to traditional expectations
  • gender fluid: a person who doesn’t identify with one gender, but rather expresses a fluid or changeable gender identity that is likely to shift depending on the situation
  • androgynous: people who present their gender as one that is not distinguishable as either male or female
  • bigender: a person whose gender includes both male and female, these people sometimes feel that one is more pronounced than the other, but both are present
  • agender: this person does not identify with a male, female, or any other gender

Gender Expression

This term refers to how a person chooses to express gender and usually this involves a person’s clothing, haircut, voice or other external characteristics. Gender expression may or may not be an expression of what society normally deems as feminine or masculine characteristics. 

Gender Role

Traditionally, gender refers to the role of each sex in society—it is influenced strongly by the cultural and social aspects of a given culture. In today’s world, instead of having a gender role that stems from a person’s biological sex, people develop gender roles in response to many things, including family interactions, education, media, friends, and the environment one is exposed to.

Gender roles differ greatly from one society to another. In some societies, gender roles are stricter than in others.

It’s important to note that gender roles are fluid, meaning they can change with time. For example, today, many men are taking on roles that were traditionally considered female gender roles, such as child-rearing. On the other hand, women have stepped into the workplace to take on gender roles that were customarily considered men’s jobs such as politicians, doctors, lawyers, managers, and more. 

What the Research Says

Scientists have known for some time that medical outcomes can be impacted by sex. For example, female menopausal hormonal changes are thought to be one factor influencing the higher incidence of Alzheimer’s disease in women as compared to men. Women also have a higher incidence of other diseases, such as osteoporosis, depression, and anxiety. Men, on the other hand, are more likely to have heart disease (early in life) and Parkinson’s disease.  

Gender Impacts Health

What researchers are discovering is that a person’s biological sex is not the only factor that influences health. A group of researchers from Canada discovered that gender roles, not biological sex, impact the recovery from a condition called acute coronary syndrome. (Acute coronary syndrome describes a condition involving blockage of blood flow to the heart that causes a heart attack.)

They observed that recovery was not dependent on the sex of the patient (male or female), but rather, it depended on a person’s gender characteristics. Those in the study who had more traits that society traditionally refers to as female characteristics, such as caregiving, were more likely to have another coronary episode (or to die within one year of the initial episode) than those with more traditional male traits, such as being the primary household breadwinner.

These findings were consistent among the study participants, regardless of biological sex. “Both sex and gender influence human health and disease,” says Janine Clayton, MD., the director of the National Institutes of Health’s Office of Research on Women’s Health.

“We don’t know how to measure gender,” says Stanford professor, Marcia Stefanick, Ph.D., director of the Stanford Women and Sex Differences in Medicine Center. “Sex is generally assigned at birth, based on the external genitalia, after which a broad range of biological, particularly reproductive, sex differences are assumed. Individuals are then, usually, forced into a binary model of gender—with distinct masculine and feminine categories—when the possibilities are much broader and more expansive,” Stefanick goes on to explain.

Stefanick suggests that researchers need to get on board with being able to recognize and identify the difference between gender and sex if medical experts want to avoid skewing the outcome criteria in studies where the results are impacted by these factors.


As researchers begin to delve deeper into learning about the impact of gender issues, scientists are discovering that both women and men are exploring “a spectrum of gender traits that aren’t purely masculine or feminine,” says Stefanick. 

The study shows that there is concrete evidence to back up the fact that how a person identifies themselves in society is real and has a tangible impact on many factors, including health. 

“We need to debunk the myth that females are mysteriously complex,” says Amy Braun, a graduate student in the laboratory of Theo Palmer, Ph.D., an associate professor of neurosurgery. Braun goes on to explain, “We need to increase literacy around the concepts of sex and gender. They are not the same."

She goes on to say, "Frankly, I think a lot of researchers just don’t want to say the word ‘sex.’ ‘Gender’ is more comfortable, and more fancy-sounding. But gender is its own biological variable, and we have to understand that and think critically about it.”

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