1. Physical Development

2. Objective
• Summarize the changes in physical, brain, and
motor development in middle childhood and
middle adolescence.

3. Theories of Physical Development
• Genetic Perspective
• Behavioral Genetics
• Environmental Development Theory
• Biological Perspective

4. Genetic Perspective
• Most development is
determined by the
child’s genes. The
environmental
influence is small.
• Ex. Physical similarities
between siblings

5. Behavioral Genetics
• Use twin and adoption
studies to demonstrate
that all behavioral,
intellectual, and
personality traits are to
some extent influence by
genetic predisposition.
• Ex. Difference and
similarities due to shared
and non shared
environments.

6. Behavioral Genetics
Shared Non-shared environment
The effects of non-shared environment are
greater.

7. Environmental Development Theory
• Genetic based theory that hold that current
pre-dispositions or behaviors are adaptive for
ancestors millions of years ago.
• Ex. Stressful early family environment leads to
early puberty for girls.

8. Biologic Perspective
• Recognizes the role of genetics, but places
greater emphasis of biological structures and
children’s functioning.
• Developmental patterns are studied and
explained by examining hormonal functioning,
brain maturation, brain chemistry, and
physiologic

9. Middle Childhood & Adolescent
Development

10. What was puberty like for you?

11. In middle childhood and adolescence,
developmental change occurs in:
– Physical development
– Motor development
– Brain development

12. By the end of middle childhood,
children engage in activities that
require:
– Fine motor coordination
– Sustained attention
– Improved balance

13. Physical changes in adolescence
include:
– Physical growth
– Changes in strength and speed
– Brain development

14. Physical Changes During Middle
Childhood
• Steady growth in body size from age 8-12
• Gain 2-3 inches in height and 4-6 pounds in
weight per year
• After age 13, when boys begin puberty they
surpass girls both height and weight
• Growth rates can vary based on genetic histories,
ethnic background, illness, and other factors
• Girls between the age of 8 and 12 are entering
puberty earlier

15. Secular Trend
• Children in almost all areas of the world are
taller and heavier
Reason
• Evolutionary – tallness genes are selected
• Environment – improvement in life

16. Changes in Body Proportions in Middle
Childhood
• Increase in body proportion
• Stature – total height which is head and neck
length, trunk length, and leg length
• Leg length increases more rapidly followed by the
trunk and then the head and neck
• Rapid growth of hands, feet and limbs
• Growth in jawbone growth and teeth eruption
(braces?)
• Facial growth – loss of the baby face

17. Skeletal Development
• Hardening and fusion of the bones
– Things that effect bone growth (lack of calcium in
diet, soft drinks, alabolic steriods, inactivity)
– 90% of skeletal mass is developed by age 18

18. Body Fat Levels and Muscle Mass
• By the end of adolescence, body fat accounts
fro 27% of total body weight in girls and 16%
in boys.
• Increase in muscle mass
• Obesity has increased in US in past 2 decades

19. Major Physical Changes in Middle
Adolescent
• Transition from infertility to fertility
• Sexual maturation
• Changes in body size, shape, & composition –
Growth spurt
• Increase hormonal production (gonadarche)
• Development of secondary sex characteristics

20. Physical Development in Middle
Adolescence
• Girls start puberty 1-2 year earlier than boys
• Boys voice deepens
• Increase in facial hair in boys
• Increase in height & body weight

21. Maturational-deviance hypothesis
• Adolescents who are off-time will show greater
adjustment problems.
• Girls who mature early have the most difficulty
time adjust to change. Physical change does not
match cognitive, social, and emotional change.
• Early maturing boys experience more anxiety and
hostility
• Late maturing boys have more psychopathology

22. Brain
• Synaptic pruning and dendritic branching,
discrimination, becoming more integrated
• During adolescence, there is growth spurts in
specific regions of the brain
• Grey matter deceases during adolescence
• Peaking of synaptic connections
• Synaptic pruning
• More efficient learning capability
• Learning a language up to 15
• Maturation of the prefrontal lobe

23. Brain
• Exposing adolescents to different and
stimulating experiences can change the
makeup of the brain significantly.
• Research shows that negative influence
(drugs, violence, stress, poverty) can have a
long term effect on the brain.

24. Motor Skill Development
In what motor activities did you excel
during adolescence?

25. Middle Childhood
• Improvement in gross motor skills
– Running – longer strides
– Jumping – vertical jumping abilty
– Thowing – throwing accuracy and distance
– Balance – stand on one foot
• Improvement in fine motor skills

26. Perceptional-Motor
• Greater reliance on visual perception
• Can use multiple senses to process
information
• Can discriminate more among the senses
• Lateral dominance
• More accurate perception of moving things

27. Motor Skills in Middle Adolescence
• Period of awkwardness for some boys
• Better at physical activities
• Improvement in intermodal coordination
• Can block out distractions
• Stronger, fast, increase in endurance,
steadiness

28. Application
• How can you use this knowledge of
adolescent development to address the needs
of adolescents?
• Create a program/assignment in which you
help promote the development of
adolescence.