A Human growth and development through
the life stages
A1 Physical development across the life stages
Infancy (0–2 years)
Development milestones
Newborn babies are helpless when it comes to muscle coordination and control. They are
unable to hold up their heads, roll over, sit up or use their hands to move objects
deliberately. Developing both gross and motor skills allows increasing and more complex
movement. By around the age of two, infants develop and use both gross and fine motor
skills as they become more independent. For example, when playing with shape-sorting
toys, they use gross motor skills to hold their body steady enough to grasp the shapes firmly
and use fine motor skills to fit each shape in the correct slot.
Early childhood (3–8 years)
Development of gross motor skills
Children’s practical abilities associated with gross motor skills continue to develop. By the
age of three, most children will be able to use pedals to ride a tricycle, run and balance on
one foot for one second. By the age of four, children may be able to kick and throw a large
ball. At five years, they can hop using each foot separately. By the age of six or seven a child
may be able to skip and ride a bicycle. At eight years old they will have good strength and
body coordination so that they can take part in many sports and activities.
Development of fine motor skills
Fine motor skills are the ability to control and coordinate smaller movements and muscles
such as the movement of hands and fingers. By the age of three, children should be able to
control their movements enough to use a pencil to copy letters or build a tower with cubes.
By the age of five, most children should be able to dress and undress on their own, including
tying their own shoelaces. At eight years of age, they will have good control of their small
muscles and be able to draw detailed pictures.
Adolescence (9–18 years)
Development of primary and secondary sexual characteristics
Puberty takes place over several years. It is a period of rapid change and growth and is
experienced by both females and males. Primary sexual characteristics relate to the changes
and development of reproductive organs, while secondary characteristics are outward signs
of development from a child into a man or woman.
Puberty in girls often starts between the ages of 11 and 13 although it may begin earlier.
Boys generally start puberty later, often between 13 and 15 years of age. Puberty is a
, development stage that prepares the body for sexual reproduction. It is triggered by the
action of hormones that control sexual development. Both boys and girls may experience a
‘growth spurt’ when they grow taller at a faster rate than before.
The role of hormones in sexual maturity
The main female hormones are oestrogen and progesterone. The ovaries start to produce
oestrogen and progesterone which are responsible for changes including ovulation and
menstruation. The first period is a significant, notable change for young females as it
indicates the onset of fertility.
The main male hormone is testosterone. The testes start to produce testosterone which
stimulates sperm production, indicating the onset of fertility. Testosterone is also
responsible for the development of secondary sexual characteristics such as a deeper pitch
and tone of the voice.
Early adulthood (19–45 years)
Physical strength peaks
Young adults are usually at the peak of their physical performance between the ages of 19
and 28. By this age, young adults have reached their full height and strength, and reaction
time and manual dexterity are also at their peak. After this age adults may gradually lose
some strength and speed, although these changes are often unnoticed outside of
competitive sport. Decline in physical capabilities may be exacerbated towards the end of
this life stage if individuals have an unhealthy diet, do not take regular exercise, and
maintain an unhealthy lifestyle.
Exercise and a healthy diet can help to develop physical fitness and athletic skills into middle
adulthood.
Pregnancy and lactation
Pregnancy and lactation are key phases in an adult female’s lifespan. During early
pregnancy, women experience many physical and emotional changes in preparation for
parenthood. Pregnancy hormones can cause mood swings.
Hormonal changes take place, with an increase in progesterone which maintains the
pregnancy, while the increase in oestrogen may be responsible for the sickness some
women suffer in early pregnancy. Hormones also affect the shape and appearance of their
breasts, including darkened veins due to increased blood supply. Nipples and areolas
darken, and breasts become more sensitive and tender, preparing the breasts to produce
milk to feed the baby.
Perimenopause
Women in perimenopause generally experience some of these symptoms:
▸ hot flushes and night sweats
▸ breast tenderness
the life stages
A1 Physical development across the life stages
Infancy (0–2 years)
Development milestones
Newborn babies are helpless when it comes to muscle coordination and control. They are
unable to hold up their heads, roll over, sit up or use their hands to move objects
deliberately. Developing both gross and motor skills allows increasing and more complex
movement. By around the age of two, infants develop and use both gross and fine motor
skills as they become more independent. For example, when playing with shape-sorting
toys, they use gross motor skills to hold their body steady enough to grasp the shapes firmly
and use fine motor skills to fit each shape in the correct slot.
Early childhood (3–8 years)
Development of gross motor skills
Children’s practical abilities associated with gross motor skills continue to develop. By the
age of three, most children will be able to use pedals to ride a tricycle, run and balance on
one foot for one second. By the age of four, children may be able to kick and throw a large
ball. At five years, they can hop using each foot separately. By the age of six or seven a child
may be able to skip and ride a bicycle. At eight years old they will have good strength and
body coordination so that they can take part in many sports and activities.
Development of fine motor skills
Fine motor skills are the ability to control and coordinate smaller movements and muscles
such as the movement of hands and fingers. By the age of three, children should be able to
control their movements enough to use a pencil to copy letters or build a tower with cubes.
By the age of five, most children should be able to dress and undress on their own, including
tying their own shoelaces. At eight years of age, they will have good control of their small
muscles and be able to draw detailed pictures.
Adolescence (9–18 years)
Development of primary and secondary sexual characteristics
Puberty takes place over several years. It is a period of rapid change and growth and is
experienced by both females and males. Primary sexual characteristics relate to the changes
and development of reproductive organs, while secondary characteristics are outward signs
of development from a child into a man or woman.
Puberty in girls often starts between the ages of 11 and 13 although it may begin earlier.
Boys generally start puberty later, often between 13 and 15 years of age. Puberty is a
, development stage that prepares the body for sexual reproduction. It is triggered by the
action of hormones that control sexual development. Both boys and girls may experience a
‘growth spurt’ when they grow taller at a faster rate than before.
The role of hormones in sexual maturity
The main female hormones are oestrogen and progesterone. The ovaries start to produce
oestrogen and progesterone which are responsible for changes including ovulation and
menstruation. The first period is a significant, notable change for young females as it
indicates the onset of fertility.
The main male hormone is testosterone. The testes start to produce testosterone which
stimulates sperm production, indicating the onset of fertility. Testosterone is also
responsible for the development of secondary sexual characteristics such as a deeper pitch
and tone of the voice.
Early adulthood (19–45 years)
Physical strength peaks
Young adults are usually at the peak of their physical performance between the ages of 19
and 28. By this age, young adults have reached their full height and strength, and reaction
time and manual dexterity are also at their peak. After this age adults may gradually lose
some strength and speed, although these changes are often unnoticed outside of
competitive sport. Decline in physical capabilities may be exacerbated towards the end of
this life stage if individuals have an unhealthy diet, do not take regular exercise, and
maintain an unhealthy lifestyle.
Exercise and a healthy diet can help to develop physical fitness and athletic skills into middle
adulthood.
Pregnancy and lactation
Pregnancy and lactation are key phases in an adult female’s lifespan. During early
pregnancy, women experience many physical and emotional changes in preparation for
parenthood. Pregnancy hormones can cause mood swings.
Hormonal changes take place, with an increase in progesterone which maintains the
pregnancy, while the increase in oestrogen may be responsible for the sickness some
women suffer in early pregnancy. Hormones also affect the shape and appearance of their
breasts, including darkened veins due to increased blood supply. Nipples and areolas
darken, and breasts become more sensitive and tender, preparing the breasts to produce
milk to feed the baby.
Perimenopause
Women in perimenopause generally experience some of these symptoms:
▸ hot flushes and night sweats
▸ breast tenderness
