Lifespan Development
Stage 1: Infancy
Infancy is the first stage of the lifespan that lasts from birth to 2 years.
Biological Development
Neonates (a baby up to one month old) can see, hear, smell, and taste, but these senses are still developing. They
can also respond to touch and pain and have reflexes that help them to survive. Reflexes include the walking reflex,
grasping reflex and crawling reflex.
In the first two years of life an infant will double in height and quadruple in weight. By seven months of age, the
nervous system has matured enough to allow babies to grasp objects, smile, laugh and sit up unaided. At about 10
months of age, children can stand alone for a short time and by approximately 15 months to 2 years of age children
will be able to stand and walk alone.
Cognitive Development
Infants are born with certain perceptual abilities. In the first few weeks of life, infants can respond to the direction of
sound, they can discriminate their mother’s voice from the voices of other people and they can even notice the
difference between two or three objects.
When infants turn their heads to look at something, this is known as the ‘orienting response’. When they choose to
look at a new stimulus over an old stimulus, this is known as ‘preferential looking’.
Preferential looking is one way to test the cognitive abilities of infants. When infants are presented with two cards,
one with patterns and one a block of colour, the infant will prefer to look at the pattern. Infants also prefer to look at
faces over any other objects.
If a stimulus such as a picture or sound is presented to infants several times in a row, they usually pay less attention
to it each time. This is called ‘habituation’.
When infants show renewed interest in a stimulus this is called ‘dishabituation’.
Preferential looking, habituation and dishabituation are ways to test the cognitive development of infants.
Language development:
1 month – babies can cry to gain attention
6-8 weeks – babies begin cooing
7 months – babies begin to ‘babble’
1 year – babies understand words such as ‘no’ and ‘hi’ and can identify and say ‘mum’ and ‘dad’
18 months – 2 years – babies go from using one word to making 2-3 word sentences
Socio-cultural Development
Self-awareness
At about 15 months of age, infants are able to recognise themselves in a mirror which demonstrates self-awareness.
Social awareness:
Around the same time as infants become self-aware, they also become aware of others. They use this awareness to
learn and guide their own actions and responses. This is known as ‘social referencing’.
Attachment:
Infants and their primary caregiver form an emotional attachment. This is very important for development in the
first year of life. An infant’s attachment is recognisable when they start to display separation anxiety when left with
people other than their primary caregivers at around 8-12 months of age.
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Stage 2: Childhood
Approximately 2-12 years of age.
Childhood is divided into two sub-stages: Early childhood (2-6 years) and Late childhood (6-12 years).
Biological Development
Growth begins to slow after age 2. Children develop the strength to walk, run and skip as well as the coordination
needed for fine motor skills such as writing and drawing.
Cognitive Development
The brain reaches 90% of its adult weight by about the age of 5 years. Children progress through two stages
according to Piaget’s cognitive development theory: the preoperational and the concrete operational stages. The
first 7 years have been found to be critical for language learning.
Socio-cultural Development
Children learn to play and through this activity they learn socially appropriate behaviour. The peer group takes on a
bigger role in a child’s life as they reach later childhood.
Stage 3: Adolescence
Approximately 12-18 years of age
Biological Development
This is the period when humans reach reproductive maturity after progressing through puberty. Both males and
females have a growth spurt (which occurs earlier in females than in males) and their bodies change due to the
effects of hormones testosterone and oestrogen.
Cognitive Development
According to Piaget, this is when individuals reach the formal operations stage of cognitive development, which they
follow into adulthood.
Socio-cultural Development
The peer group has an important role, with many adolescents conforming to their group norms. Depending on when
puberty begins, this can have an effect on the self-esteem of young people.
Stage 4: Early Adulthood
Approximately 18-40 years of age.
Biological Development
Individuals reach their physical peak in early adulthood and then, towards the end of this period, begin to decline.
Cognitive Development
The final stage of Piaget’s theory, the formal operations stage, is continued from adolescence through the remaining
years of life.
Socio-cultural Development
Many individuals become independent, supporting themselves financially and developing social relationships.
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Stage 5: Middle Age
Approximately 40-60 years of age.
Biological Development
Individuals have a sensory function decline, mostly in the eyes and ears. Physically, middle age people have a decline
in muscle mass and therefore strength. This decline can be slowed somewhat by careful exercise and diet control.
Menopause occurs on average at 51 years of age, when women stop menstruating and become unable to
reproduce. Men do not undergo any physical change that is comparable to menopause, although there is a reduction
in testosterone, men are still capable of reproducing.
Cognitive Development
Most cognitive skills remain stable, though there may be some changes to memory function, mostly in the ability to
recall information. Other methods such as recognition appear to remain stable.
Socio-cultural Development
Many individuals retire from work during this period. Individuals who are active socially and mentally and have a
purpose in life appear to have better wellbeing during this period life.
Stage 6: Old Age
Approximately 60 years of age and onwards.
Biological Development
Physical decline such as muscular strength, flexibility, circulatory efficiency, sensory acuity and other functions.
Cognitive Development
The effects of ageing depend greatly on the lifestyle an individual has led up until old age, and genetics also play a
role. Contrary to popular belief, intelligence test scores show very little decline with ageing, but this may depend on
the type of activity being tested.
Socio-cultural Development
Individuals with close social relationships report better wellbeing.
TASK
Use the above notes and the information in your textbook to create a poster that shows the stages of a lifespan.
Include:
- The names of each stage and the age bracket
- 3 key points of biological development for each stage
- 3 key points of cognitive development for each stage
- 3 key points of socio-cultural development for each stage
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