Information for Teenagers – Gender Development: The Inside Story 

(This information has been specifically designed to discuss and explain gender development to teenagers, of school years 10 and 11 upwards.  It is reproduced courtesy of GIRES, link below).

We all know that boys and girls are different.  Boys and girls look different, they often behave differently, and they feel different.  Outside appearances of the sex of our bodies—the genitalia—are the indicators we all recognise, but internally too, the organs of reproduction are different, and, importantly, so are small areas of the brain.  The process of developing into ‘male’ and ‘female’ is called ‘sex-differentiation’. There are complicated reasons for this development.

‘Genes’ (made up of sections of the double helix DNA) are located on the chromosomes which are in all the cells of the body.  Genes carry the codes for those bits of us that we inherit from our parents; genes influence how we look and how we develop.  They have an effect on how we start life before birth, and how we grow afterwards.  Genes affect our development as boys and girls.


For many years, scientists have understood that genes affect the way our bodies manufacture, and use, ‘hormones’.  Right at the start of life in the womb, a baby is equipped to develop either way, as male or as female but if certain genes, found on the Y chromosome, are present, they will trigger the production of the hormone, testosterone.  Typically, in the presence of testosterone the baby will be born looking like a boy; without testosterone a baby will be born looking like a girl.  Recent research suggests that, in addition to these hormonal effects, certain genes may act directly on the brain to trigger its differentiation into ‘male’ and ‘female’.  Whatever the cause, science shows that small areas of the brain are structurally different between men and women, and appear to be ‘programmed’ so that each experiences a strong predisposition to ‘feel’ like one or the other.  This feeling of being a boy or a girl, a man or a woman is called our ‘gender identity ’ or, sometimes, ‘core gender identity’.

 The vast majority of us experience our gender identity in a way which is consistent with the way our bodies look on the outside.  Consequently, all new-born infants are expected to grow into adulthood ‘feeling’ the same way that they ‘look’. If a baby is born with a penis, he will be regarded as a ‘boy’ and if the baby doesn’t have a penis, she will be regarded as a ‘girl’.  Each is expected to be comfortable with his or her body and both are expected to be comfortable with their social roles, also known as their ‘gender roles’.  It is anticipated that boys will want to grow up to be men, and girls, to be women.

But a few individuals are very special. Recently scientists have found evidence that, in a small minority of people, at least one of the ‘sex-differentiated’ areas of the brain is ‘female’ in people who look male on the outside, and ‘male’ in people who look female.  This unusual development of the brain appears to be associated with a gender identity that is also, therefore, at odds with the external appearance.  So, an individual who looks like a man may identify as a woman, and vice versa.  This mismatch between the way individuals look and the way they identify themselves, creates a feeling of acute discomfort which is called gender variance or dysphoria (dysphoria means unease or unhappiness).  This is not an illness, but it does mean that an individual may find that it is absolutely impossible to continue living in the gender role of, for instance, a girl, with the prospect of growing up to be a woman.  The person will know that he is actually a boy so, understandably, he needs others to accept that too.  He cannot continue to behave like a girl because, in the place which counts most, the brain, he isn’t a girl.  Conversely, an individual who has grown up apparently as a boy may, nonetheless, identify as a girl and will need to live, and be accepted, as a girl who will become a woman.  Many individuals try to hide their discomfort and they struggle to conform to behaviour typical of the gender in which they are raised.  Ultimately, though, the need to bring the gender role in line with the core gender identity may become overwhelming.  The process of changing the gender role is called ‘transition’.

Some young people experiencing this condition will seek treatment to block the physical changes of puberty (for example: breast development in girls; and in boys, facial and body hair and the Adam’s apple associated with the deepening of the voice).  The suppression of the pubertal changes gives the young people time to be sure that they really do need to change permanently to the other gender role.  Then when they are deemed old enough to make a final decision, usually not before the age of 16, they may be treated with what are called ‘cross-sex hormones’ (oestrogen for someone who identifies as a girl, but looks like a boy—and testosterone for someone who looks like a girl, but identifies as a boy).  Later, usually not before 18, they may have surgery to bring the bodily appearance in line with the core gender identity.  However, most individuals will not have these treatments until they are older, and some delay transition and medical treatment for many years.

Those who continue to live, as adults, in the gender role which is consistent with their core gender identity are called transsexual people or trans people.  If they have undergone transition from living as a woman to living as a man, they may be known as trans men; conversely, if they have transitioned from living as a man to living as a woman they are trans women.  In their new gender status, they should be regarded simply as men or women.  In 2005, trans people became entitled to follow a legal process through which they may obtain a Gender Recognition Certificate and new birth certificate recognising their post-transition gender status simply as men or women.  This allows them to get on with their ordinary lives whilst enjoying the same social rights as everyone else.


Gender identity has nothing to do with sexual orientation.  Trans people, like anyone else, may be gay, lesbian, bisexual or straight (heterosexual).

Individuals who experience this gender variance and who are willing to reveal their true selves, show great courage.  They have earned our respect and they deserve our support.  Nature is very varied and the differences between us are what makes human beings so special and interesting.  We don’t all fit into neat little boxes.

© 2013 GIRES