Biological Psychology: Stress

• Behaviour explained by hormones, genetics, Nervous system & evolution.
• All behaviour can be explained using Biological causes, modifiying or removing unwanted behaviour using Biological treatments (medication).
• Research can be conducted using animals, by informing researchers about human behaviour and Biologcial influences due to human and animal similarities. Methods include; Experiments, Correlations, Cast Studies, Questionnaires and Interviews.

Strengths:

• Scientific and can provide evidence to support or disprove theories.
• Biological treatments can be developed easier to suit different individuals.

Weaknesses:

• Doesn't take individual differences, environments, families, social situations or childhood experiences into account.
• Can cause indivuduals avoiding responsibility for negative behaviour.

Stress...

• A response to stimuli in the environment.
• An alarm reaction involving a series of changes in the body.
• Occurs when we are in a mentally or physically demanding situation.  
• A feeling of not having the ability to cope with demands.

Stressor...

• Something that triggers the stress reactions in the body.
• These include workplace and life events such as divorce.
• These can vary between people depending on their sense of control.

Effects of stress...

• Heart rate, Blood sugar & Blood pressure increase.

Stress and illness...

• Direct effect: Cardiovascular (heart disease & atherosclerosis).
• Indirect effect: substance and alcohol misuse.

Selye's General Adaptation Scheme

• The reaction is the same whatever the stressor.
• Stress (can cause long-term effects)

1. Alarm: The shock phase.
2. Resistance: High levels of stress chemicals start to damage the immune system.
3. Exhaustion: Energy levels fall. Illnesses develop.

Evaluation

• Too simplistic.
• It was the first successful attempt to link stress and illness together. 
• The exhaustion stage doesn't occur as hormones 'run out' said by Selye.

HPA: Chronic
1. Hypothalmus - 2. Pituitary Gland - 3. Adrenocorticotropic Hormone - 4. Adrenal Cortex - 5. Cortisol Steroids.

Friedman & Rosenman (1974): Stress & Cardiovascular disease
Aim: To investigate links between Type A personality & Coronary Heart Disease.
Method: 3,200 men tested for A/B personality and health assessed for 3.5 years.
Results: Twice as many Type As as Type Bs developed Coronary Heart Disease.
Conclusion: Type A behaviour increases the risk of Coronary Heart Disease.
Evaluation: Correlational study, so no proof of cause and effect. Self-reported questionnaire may give investigator effect.

Keicolt-Glaser (1995): Stress and the Immune System:
Aim: To investigate the effect of stress on the immune system.
Method: 75 medical students gave blood a month before exams & during exams.
Results: Less NK (Natural Killer) Cells were found during the exam period.
Conclusion: Exam stress reduces immune function.
Evaluation: Correlational study, so not proof of cause and effect. A Natural experiment with high ecological validity. 

(HAN)SAM: Acute
1. Hypothalmus - 2. Autonomic Nervous System (ANS) - 3. Adrenal Medulla - 
4. Adrenaline and Noradrenaline.

Affects on the body: 

• Blood pressure and heart rate increase - to move blood around body faster with quicker activity.
• Digestion decreases - blood can be directed to the brain and muscles.
• Muscles become more tense - body is more responsive physically.
• Perspiration increases - so the body cools and burns more energy.
• Breathing rate increases - so more oxygen can be sent to muscles.

These happen very fast, in order to prepare us for the 'fight or flight' response.

Kranz et al (1991): Stress and the heart

Aim: To investigate the effects of stress on the heart.

Method: Lab experiment, 39 participants (not on heart medication) took part in one out of three tasks (maths test, stroop test, public speaking). Their blood pressure and level of contracting blood vessels around the heart were measured.

Results: Participants with highly contracting blood vessels showed the highest increase in blood pressure.

Conclusion: Stress has a direct influence on the function of the body, increasing the risk and likeliness of cardiovascular disorders.

Evaluation: It has not been shown that one causes the other, only correlation. Not everybody shows same reactions to activities; individual differences. Laboratory experiment - low ecological validity with well-controlled variables.

Kranz et al (1991): Stress and the heart

Aim: To investigate the effects of stress on the heart.

Method: Lab experiment, 39 participants (not on heart medication) took part in one out of three tasks (maths test, stroop test, public speaking). Their blood pressure and level of contracting blood vessels around the heart were measured.

Results: Participants with highly contracting blood vessels showed the highest increase in blood pressure.

Conclusion: Stress has a direct influence on the function of the body, increasing the risk and likeliness of cardiovascular disorders.

Evaluation: It has not been shown that one causes the other, only correlation. Not everybody shows same reactions to activities; individual differences. Laboratory experiment - low ecological validity with well-controlled variables.

Holmes & Rahe (1967): Created a list of 43 common life events and asked participants to score them on a basis of how stressful they were. The higher the number of Life Change Units (the umbers that made up each score), the more stressful it was. E.G. Death of Spouse = 100 LCUs, Divorce = 73 LCUs, 
Christmas = 12 LCUs. 

Rahe et al (1970): LCU score and illness