Human growth and development

• Infancy


  0-3 years old
• Physical growth in infancy


  • Average length at birth is 51cm, increases to 75cm by 1 year and 94cm by 3 years
  • Weight doubles from average birth weight of 3.3kg by 6 months and triples by 1 year, average weight of 14kg by 3 years
  • Milk teeth first appear at 6 months, full set of 20 teeth by 2-3 years
• Gross motor skills in infancy

  • Can kick legs vigorously by 3 months
  • Can sit with support and roll over by 6 months
  • Can crawl and shuffle by 9 months
  • Can walk alone by 12-18 months
  • Can walk down stairs with hand held, roll and throw ball by 18 months
  • Can walk on tiptoes and pedal a tricycle by 3 years
• Fine motor skills in infancy


  • Adapts grasping reflex by 4 months to hold a rattle
  • Can pass object from one hand to another by 6 months
  • Develops pincer grip/grasp by 9 months to pick up small items
  • Has developed neat pincer grip/grasp by 12 months to pick up items from floor or stack cubes
  • Can hold a crayon and scribble by 18 months
  • Can draw circles and dots, build a tower of 6 bricks by 24 months
  • Can turn pages in a book, draw a face, thread large beads by 36 months
• Language and vocabulary development in infancy


  • Makes noises when spoken to, makes non-crying noises like cooing and gurgling by 1 month
  • Babbles and uses monosyllables like 'ga ga' by 6 months, understands words like 'mama' and 'dada'
  • Speaks a few recognisable words and understands many more by 12 months
  • Uses up to 40 recognisable words and uses phrases by 18 months
  • Can speak over 200 words, uses telegraphic speech by 24 months
  • Can talk in sentences and carry on simple conversations by 36 months
• Cognitive development in infancy


  • Recognises primary carer by 1 month
  • Takes interest in surroundings by 3 months
  • Understands objects and what to expect from them by 6 months
  • Understands names of body parts, can identify pictures of a few named objects by 15 months
  • Begins to understand consequences of own and others' actions, can follow simple instructions by 24 months
  • Can match primary colours, begin to understand concept of time, are fascinated by cause and effect, can sort objects into simple categories by 36 months
• Emotional and social development in infancy


  • Forms bond with main carer, enjoys being cuddled and cared for by others, has capacity to show affection
  • Develops stranger fear and separation distress around 6 months, indicating attachment development
  • Shows evidence of multiple attachments by 8 months, less anxious around strangers by 12 months
  • Develops independence as becomes more confident in doing things for themselves, e.g. feeding
  • Develops control of emotions, displays negative behaviours like temper tantrums around 24 months as can't express themselves, more able to control emotions by 36 months
  • Smiles at faces around 6 weeks, beginning of social development
  • When attached, may not play with other children or on their own due to fear of separation
  • Progresses from solitary play at 2 years to parallel play at 2.5 years to cooperative play at 3 years, opportunities to mix with other children
• Childhood


  1. 10 years old
• Physical development in childhood


  • Increase in weight from approx 6kg at 4 years to 29kg at 6 years to 25kg at 8 years to 31kg at 10 years
  • Increase in height from approx 102cm at 4 years to 116cm at 6 years to 127cm at 8 years and 137cm at 10 years (growth spurt between 5-7 years)
  • Loses baby features, becomes more adult in appearance
  • Baby/deciduous teeth replaced by permanent teeth from 5-7 years
  • Gains full bladder and bowel control
  • Gross motor skills like running and climbing continue to develop, become faster and stronger
  • Fine motor skills like holding a pencil, brush, tying laces develop, control and coordination improve
• Intellectual development in childhood


  • Vocabulary increases, can say and understand more complicated sentences
  • Learns to read and write
  • Curiosity develops, asks lots of questions, likes to know factual information
  • Understanding of numbers develops, problem-solving skills increase, can do simple arithmetic
• Emotional development in childhood


  • Better control over emotions, can cope better with emotions like anger, jealousy, frustration, criticism
  • Experiences a wider range of emotions than infants, can think about feelings of others, develop empathy
• Social development in childhood


  • Still dependent on family and carers but independence increases, can cope with short separations like going to school
  • Self-confidence increases
  • May feel lonely, rejected, isolated if bullied or abused, high self-esteem if loved, valued, cared for
  • Cooperates with other children in games, understands rules and fairness, approval of friends becomes important
  • Develops social skills like table manners, turn-taking, cooperation
  • Attachment to parents is still noticeable, although weaker
• Adolescence


  11-18 years old
• Physical development in adolescence


  • Males: Penis and testes grow larger, growth of pubic, facial and underarm hair, muscles develop, chest and shoulders broaden, larynx grows, voice breaks and deepens, ability to ejaculate sperm, growth spurt

  Females: Hips widen, skin problems, growth spurt, breasts develop, beginning of menstruation/periods
• Intellectual development in adolescence


  • Able to imagine and think about things they have never experienced
  • Learn to think in different ways, understand more difficult concepts
  • Able to solve problems, think things out logically
  • Think about future/career
  • Preparation for exams through education system
  • Development of skills through part-time job
• Emotional development in adolescence


  • Relationships with parents may be difficult, disagreements about clothes, makeup, friends, going out
  • Mood swings, happy and excited one minute, sad and down the next
  • Aggressive behaviour, get angry very quickly and show aggression to others
  • Independence increases, become less dependent on parents, have part-time job
  • Increased stress, worry about exams, coursework, relationships
  • Intimate relationships, may have relationships, fall out, be hurt
  • Low self-esteem, lack confidence and feel insecure due to body changes, relationships, performance at school
  • Relationships with friends may be difficult
• Social development in adolescence


  • Become more dependent on peer group, opinion of peers becomes very important
  • Desire to belong to a group, need to fit in with a group
  • Exploring sexuality, experiment with sexual relationships
  • Develop independence from parents
  • Larger range of social contacts, e.g. at school, youth clubs, teams, social media
• Early adulthood


  19-39 years old
• Physical development in early adulthood


  • Reproductive peak is reached
  • Growth completed
  • Signs of ageing begin to show nearer the end of this life stage, e.g. hair going grey, wrinkles appearing, men going bald
• Intellectual development in early adulthood


  • May be at university studying
  • Training/getting a job, learning new skills
  • Leaving home, learning to cope living independently
  • Managing a home/budget
  • Learning parenting skills as this life stage progresses
  • Taking up new hobbies
  • Further training at job
  • Opportunities for travel to learn about new places and cultures
  • Increasing vocabulary through education, training or employment
• Emotional development in early adulthood


  • May look for a steady relationship to experience positive emotions
  • May get married, feelings of love, security, bonding with partner
  • Before children/early stage: may have children, bonding, feelings of love, security, feeling valued
  • Relationship problems/break-ups/divorce may lead to anger and stress
  • May experience stress due to financial problems, work issues or exams/study
• Social development in early adulthood


  • Before children/early stage: time to go out, few commitments, time/money for holidays, range of friendships and relationships, e.g. at work, university, clubs

  Raising a family: less time to go out, need a babysitter, perhaps less money to socialise, make new friends with other parents, less contact with old friends
• Middle adulthood


  40-64 years old
• Physical development in middle adulthood


  • Signs of ageing continue to show, e.g. going grey, wrinkles appearing, men going bald
  • Women will experience the menopause, periods stop, no longer able to have children
• Intellectual development in middle adulthood


  • Better at making decisions, problem solving skills are well developed
  • May be promoted at work, developing/stimulating intellectual ability
  • May have more time to take up hobbies, travel, etc.
  • Reaction times may be slower, more difficult to remember things under pressure
• Emotional development in middle adulthood


  • Clear sense of identity
  • Feelings of loss due to bereavement, e.g. parents/friends die
  • Feelings of loss when children grow up and leave home (empty nest syndrome)
  • Bonding with grandchildren
  • Will have to deal with a range of emotions, e.g. anger if relationships break down
• Social development in middle adulthood


  • Early stage/rearing a family: less time to go out so relationships with friends may weaken, stress from work/caring for elderly parents, may need a babysitter, may have less money to socialise, make friends with other parents, may lose contact with old friends, take part in family activities/holidays

  Later stage/family grown up: less financial pressure, more time to go out, time to take up new hobbies, interest make new friends, social activities with grandchildren, time may be taken up looking after elderly parents
• Later adulthood


  65+ years old
• Physical development in later adulthood


  • Height may decrease as intervertebral discs in spine become thinner and posture becomes bent
  • Skin wrinkles/loses elasticity
  • Hair thins/goes bald in many men and smaller proportion of women
  • Bones become weaker, leading to osteoporosis and physical frailty, increased risk of fractures
  • Body organs/systems become less efficient
  • Sight may decline as lens loses elasticity, making it harder to focus on close objects
  • Hearing may deteriorate, quiet and high-pitched sounds become more difficult to hear
  • Mobility may decrease due to muscle wastage, brittle bones, stiff joints
  • Sense of taste/smell deteriorate due to changes in nervous system, increased risk of hypothermia
  • More prone to chronic illnesses like diabetes, heart disease
  • Weakened immune system leading to getting ill faster and more frequently
• Intellectual development in later adulthood


  • May have difficulty remembering things quickly, becoming forgetful
  • Reaction times may be slower
  • May become confused due to dementia
  • May make better decisions as they have more experience
  • May take longer to absorb new information
  • May develop new intellectual skills due to travel, hobbies, ICT clubs etc as they are retired
  • May lose skills due to retirement/no longer working
• Emotional development in later adulthood


  • Self-concept may be affected by retirement, may feel worthless, devalued as a result of not working
  • May be stereotyped by others as being less able
  • May feel loved, valued by family
  • May feel a sense of achievement after years of work
  • May feel a burden/useless, resulting in reduced social life and friendships deteriorating
• Social development in later adulthood


  • More time to meet new friends/go on outings
  • May be unable to get out due to poor health/mobility problems, miss out on opportunities to see friends/family
  • May miss contact with work colleagues
  • Lack of income, death of partner/friends causing isolation/loneliness
  • More time for family, friendships
  • Bereavement leading to a smaller family/friendship circle