human development physical development and biological aging
TRANSCRIPT
Human Development
Physical Development and Biological Aging
Physical Growth: Height and Weight Infants double their weight by four
months and triple it by their first birthday
Early childhood: girls are slightly smaller/lighter than boys
Middle/late childhood: children grow 2-3 inches per year and double their strength capacities
The Role of the Environment
Urban, middle SES first born children were taller than rural, low SES, later born children
Nutrition influences height and weight differences
Unusually Short Children
• Congenital factors
• Growth hormone deficiency
• Physical problems developed in
childhood
• Maternal smoking during pregnancy
• Emotional difficulty
Puberty
Rapid physical maturation Hormonal/bodily changes
Role of genes and environments
Pubertal Growth Spurt
Fig. 3.3
Changing Trends in Puberty
Onset of puberty beginning earlier
United States: menarche at 15 in 1840s, now
12½
Caucasian girls at average age of 10
African American girls at average age 8 to 9
**How does this impact development?
Body Image in Puberty
Throughout puberty…
Girls’ dissatisfaction increases — body fat increases
Boys’ satisfaction increases — muscle mass increases
What factors influence body image?
Early vs. Late Maturing Boys
Early maturing boys perceive themselves more positively and have more successful peer relationships than late maturing boys
Early Maturing Girls
Early maturing girls: At risk for smoking, drinking,
depression, eating disorders Tend to have older friends Earlier dating/sex Lower educational/occupational
attainment Higher incidence of mental disorders
Early Adulthood
Subtle physical changes Many reach peak of muscle tone
and strength in late teens and
twenties
Peak in joint functions in twenties
Decline in the thirties
Middle Adulthood
Lose height, gain weight Blood pressure/cholesterol increases Fertility declines:
Women: menopause Men: reduced sperm count (fertility is not
lost)
Late Adulthood
Increased risk for physical problems
Weight tends to drop after age 60
The Brain
Recent research:
Both heredity and environment shape the brain
The role of experience and brain plasticity
The Brain’s Four Lobes
Fig. 3.7
Functions of Lobes of the Cortex
Frontal lobes
Occipital lobes
Temporal lobes
Involved in voluntary movement, thinking, personality, and intentionality or purpose
Function in vision
Active role in hearing, language processing, and memory
Parietal lobesRoles in registering spatial location, attention, and motor control
The Neuron
Fig. 3.8
Experience and the Brain Mice in deprived vs. enriched
environments: differences in brain weight, neural connections and activity
Children reared in deprived environments have depressed brain activity (i.e. Romanian orphans) Can be reversed; brain plasticity/resilience
Experience and the Brain Exposure to trauma:
PTSD: reduced size of the hippocampus
Depression: Parts of the brain atrophy over time
Addiction: Changes in neurotransmitters
Pruning
Changes to the dendrites and synapses Connections are formed and
terminated
Dendritic Spreading
Fig. 3.11
The Brain in Adolescence
The adolescent brain is still growing
Emotional processing differences between adolescents (10-18 years) and adults (20-40 years)
Adolescents: Gut responses Adults: rational, reasoned responses
Differences in the parts of the brain used to process emotional information
The Brain in Adolescence
Adolescent emotions — Areas of the brain involved in emotional
regulation are still growing/changing
Poor self-control; seek rewards and pleasure
Seek novelty; increased risk-taking
Lack of practical experiences; immature
judgment **importance of parental involvement/limit setting
Preventing Brain Diseases
Positive emotions linked to longevity
Intellectual stimulation
Folic acid reduces risks and damage
Life Expectancy
Life expectancy — number of years that an average person born in a particular year will probably live
Impacted by heredity and environment
Life Expectancy
Females average 80 years, 74 years for males
Men are more likely to die from leading causes of death (respiratory diseases, accidents, suicide, cirrhosis of the liver, heart disease)
Role of lifestyle, workplace stress, heath habits
Centenarians
Individuals who live to 100: Women who have never married Ability to cope successfully with
stress Education, health, and lifestyle Individual personality traits
**Highest ratio in Okinawa: why?
Fig. 3.20
Risks of Dying from Cancer in Okinawa, Japan, and the United States