Sex vs. Gender: What’s the Difference and Why Does it Matter?

We tend to use the words “sex” and “gender” interchangeably, but they are in fact two different concepts. For many, their sex and gender are aligned, but for others, they are not.


Sex refers the physical and biological aspects of an individual, which make someone biologically male or female, such as chromosomes, hormones, and reproductive anatomy. Sex is typically assigned at birth. We can be assigned as either male, female, or intersex.

Intersex refers to those individuals who cannot be categorized as male or female across all traits. This could include people with ambiguous genitalia, people whose chromosomes are not XX or XY, or people whose external genitalia and internal reproductive organs do not align.

Males and females have distinct sex chromosomes, hormones, external genitlia, internal reproductive organs, and secondary sex characteristics. Sex assignment typically happens at birth based on these markers.


A person whose sex is female typically has two X chromosomes, the hormones estrogen and progesterone, a vulva, a uterus, a vagina, and ovaries.

They also tend to display secondary sex characteristics such as breast development, body fat, oily skin, acne, a higher-pitched voice, and widened hips.


Male-assigned individuals typically have one X and one Y sex chromosome, higher levels of testosterone, a penis, a scrotum, and testes.

They also tend to display secondary sex characteristics such as hair growth, oily skin, acne, body odor, a deepened voice, wider shoulders, and more lean muscle mass.


Intersex refers to those individuals who cannot be categorized as male or female across all traits. This could include variations in sex chromosomes, external genitalia, or reproductive organs.

While intersex babies are usually assigned as male or female at birth, they might identity themselves as another gender identity or non-binary later in life.


Gender refers to the socially constructed roles, expectations, and behaviors that are often ascribed to the different sexes. Gender identity is a personal, internal perception of oneself and is based on socially constructed roles, behaviors, and customs.

Gender is not made up of binary forms, but rather gender is a broad spectrum and can change over time.

The gender category someone identifies may not match the sex they were assigned at birth. Gender identities can include cisgender, nonbinary, agender, genderfluid, or transgender.

There are many ways outside of these identities which a person may define as their own gender.

Cisgender refers to someone whose sex assigned at birth matches their gender identity.

Nonbinary refers to someone who identifies beyond man or woman or as neither a male nor female. Agender refers to someone who does not have a gender.

Genderfluid refers to someone whose gender fluctuates over time.

Transgender refers to someone whose gender identity is different from the sex assigned at birth. Some nonbinary people consider themselves transgender but some do not.

Gender non-conforming is when an individual’s appearance, behaviour, interests, and self-concept vary, either from the norms attributed to their biological sex, or from masculine or feminine general norms in general.

Gender Expression, Identity and, Roles

People identify and express their gender in a variety of ways. Your gender identity is how you feel inside and  your own personal understanding of your gender. Gender expression refers to how a person chooses to present themselves to the outside world.

This could include one’s name, pronouns, clothing, haircut, voice, or mannerisms. Gender can also refer to the socially constructed characteristics of women and men.

This could include norms, roles, and relationships with others. Gender roles are largely based on society and culture. Gender identity and expression originate from ideas about which traits and roles are perceived as masculine or feminine in a particular culture.‌

For example, in Western cultures, stereotypically feminine traits include nurturance, sensitivity, and emotional vulnerability, and stereotypically masculine traits include self-confidence, aggressiveness, and competitiveness.

What is gender conformity?

Gender influences the way people perceive themselves and each other, how they act and interact. Gender being socially constructed means that gender roles often appear when humans live in groups together and thus, they can vary from culture to culture.

In a lot of Western cultures for instance, there are two widely recognised genders: men and women. In these cultures, are gender ‘norms’, which are ideas about how women and men are expected to be and act.

For instance, women in certain cultures are thought to be caring and maternal, whereas men are thought to be stronger and more assertive.

The concept of gender conformity is based on these gender norms. If someone is gender conforming, it means they prescribe to the gender norms that are expected of their biological sex.

The term gender conformity is rarely used as it is not common that someone is 100% gender conforming. The majority of people may conform to gender norms in some ways but subvert it in other ways.

For instance, a gender norm in many cultures is that women do not work and should stay at home to raise their children. In today’s society, it is more common that women will work, so these women would be considered as not conforming to their gender roles.

Historically, gender roles have been attributed to the biological differences in men and women. They are the product of interactions between individuals and their environmental and what sort of behaviour is expected to be appropriate based on a person’s sex.

Appropriate gender roles are defined according to the beliefs that society has about the differences between the sexes.

Below are some ways in which men, women, girls, and boys are often described as in many cultures:

  • ‘Men are the leaders’
  • ‘Women are nurturing’
  • ‘Men are more aggressive’
  • ‘Women are emotional’
  • ‘Girls like pink’
  • ‘Boys like blue’
  • ‘Girls wear dresses’
  • ‘Boys don’t cry’

Issues with gender roles

Once a child is born and their sex is revealed as either ‘boy’ or ‘girl’, often they are then figuratively put into a box of either one of two genders. These boxes are their society’s gender norms for what is expected from them according to their sex.

Boys may often be dressed in blue and encouraged to play with toys which are stereotypically made for boys such as toy cars; girls may often be dressed in pink and encouraged to play with toys which are stereotypically made for girls such as dolls.

As a society, people may put children into these gender role boxes as a way to make sense of gender and because it is what is considered ‘normal’ according to their culture.

There are many ways in which gender roles can be harmful to individuals. Gender roles often force people to perform what is expected of them according to their biological sex rather than living the way that they may choose to.

For instance, as stated previously, there is a gender norm in many cultures which states that men are meant to be more assertive than women.

Therefore, if a woman is seen as being assertive, they may often be criticised or viewed negatively to others because she is not conforming to what is expected of her gender.

Likewise, a man may wish to dress more typically feminine such as wearing makeup or a dress, however he may be ridiculed for dressing like this and may feel restricted in what he can wear.

Gender roles can limit what a person can or cannot do, reducing a person’s life to what they should do according to society’s rules. When someone breaks out of their norms, they may be at a risk of bullying or even violence in the most extreme cases.

Often, gender roles are so ingrained in a culture that anyone who doesn’t conform is viewed as strange and a target for abuse. Sometimes, people who do not conform to gender roles are forced back into their roles to avoid this abuse from others, which can cause a lot of unhappiness.

Because of gender roles, women may feel unable to put themselves forward for a job or promotion they are qualified for if that position is usually occupied by men.

They may fear being in a leadership role for fear of being labelled bossy or being undermined by others. When women and girls assert themselves, they may get told ‘girls shouldn’t talk that loud’ or ‘girls should be quiet and polite’.

Women and girls may therefore have less opportunities for success in life if they are being told these things. On the other hand, men may feel unable to express their emotions for fear of appearing too feminine and being criticised by others.

Often, men and boys are told that ‘boys shouldn’t cry’ and that they should ‘man up’ instead of discussing their emotions.

This can be very damaging for men’s mental health if they cannot express talk about their problems. They may also be less likely to seek help for a mental health problem and there is also a risk of suicide for these men.


Clements, K. C. (2019, January 24). What’s the difference between sex and gender? Healthline. Retrieved from

Newman, T. I. (2021, May 11). Sex and gender: Meanings, definition, identity, and expression. Medical News Today. Retrieved from

Stoller, R. J. (1964). A contribution to the study of gender identity. The International Journal of Psychoanalysis, volume 45 issues 2 to 3, pages 220 to 226.

Saul Mcleod, PhD

BSc (Hons) Psychology, MRes, PhD, University of Manchester

Educator, Researcher

Saul Mcleod, Ph.D., is a qualified psychology teacher with over 18 years experience of working in further and higher education.

Julia Simkus

Research Assistant at Princeton University

Undergraduate at Princeton University

Julia Simkus is a Psychology student at Princeton University. She will graduate in May of 2023 and go on to pursue her doctorate in Clinical Psychology.