For many people the subject of sexual development in children is something they would rather not think about. Parents of teenagers must accept the inevitability of their children becoming adults and engaging in normal and healthy sexual relationships. However, the developmental process starts a long time before adulthood or the teenage years. Ultimately, sexual development is a journey that starts at the moment of the child's conception when their biological gender is determined by the presence of a y-chromosone or not. From birth the fact that they are a boy or a girl determines the way they are treated, the opportunities they are given and how the child defines themselves in the complex social world. Thus, sexual development is not only about the physical changes that a child undergoes to reach maturity. It is also about the social and psychological behaviours they engage in as part of their preparation for sexual maturity.
Physical changes at puberty
The physical development of the reproductive organs is completed during the long process of puberty during adolescence. This is also the period when there is rapid growth of the body and the child is transformed into an adult. In girls, the onset of menstruation can occur from about 8 years old though the majority will begin between 12 and 15 years. A few girls will be later than this. Boys tend to reach puberty later than girls and this is often seen in the differences in height between the genders around 11 to 13 years. In boys, maturity of their reproductive organs is signalled by involuntary ejaculations in their sleep, during what is euphemistically called 'wet dreams'. Both genders undergo body shape changes. Girls become wider at the hips and breast development begins. Boys become broader at the shoulders with relatively narrow hips. Hair growth under the armpits and around the reproductive organs occurs. In boys facial growth tends to come towards the end of puberty. Puberty also starts significant changes in brain structures and functionality. These changes affect adolescents ability to assess risk and empathise. Age of onset of puberty is affected not only by our genetic make-up but also by environmental and social factors.
Major milestones in physical sexual development
Gender established at birth. Children are born with the physiology of sexual arousal: boys are capable of an erect penis and girls can produce vaginal lubrication.
Boy's testicles descend.
Puberty begins for some children from age of 8 or 9. A few are now capable of pregnancy.
Most children begin and complete puberty. Growth spurts transforms child into adult. Differences in body shape between genders. Capable of reproduction.
From birth gender determines how a child is treated not only by society but by parents and other family members. Even in parents who try to ignore gender stereotyping there are real differences in the way they interact with their child based on their sex. Research into differences between the sexes in terms of their respective physical and intellectual strengths and weaknesses is ongoing. Apart from differences in sexual reproductive organs there are other physical and sensory differences between the genders which are mainly biological in origin. With regard to intellectual differences it is much less easy to be certain of whether they have a genetic origin or are a result of social conditioning. What is clear is that differences between male and female brains are less significant than popular culture suggests and certainly no basis on which to suggest superiority of one sex over another.
Our sex is defined by our genetic code but our gender and what it means to be male or female is mainly a product of the cultural influences on us from birth. How we personally identify with our gender at a psychological level is thus a combination of biology and environment. For the majority gender identity and biological sex are the same but not for all. Many children go through a period of identifying more with their opposite gender. This is normal and meaningless in terms of their future sexuality. However, for a very few small minority they can feel that their body sex does not reflect who they are and will need professional counselling and support with this.