ATTITUDES - Meyer and Gast (2008)
Surveyed 10-12 year olds and found a positive correlation between peer influence and disordered eating.
- Attitudes to food are more than a product of social learning alone.
- Self-report techniques are not accurate.
- Only a small span of ages.
- Correlations do not give us detailed accounts and opinions.
- Correlation does not necessarily tell us cause and effect.
- Friendships are formed by similar types of personality, certain types of people may be more prone to disordered eating.
ATTITUDES - Ball and Kenardy (2002)
Of 14,000 women, the longer they spent in Australia, the more likely it was that they had acquired Australian attitudes. This is called the acculturation effect.
- Large sample size.
- It is difficult to measure how far someone has adopted ideas.
- This measure of effect may be subjective to the researcher.
- This research would have used self-report techniques such as interview, which may be inaccurate.
ATTITUDES - Dornbusch et al (1984)
Higher-class individuals had a greater desire to be thin in 7,000 American adolescents.
- Large sample size.
- Only used adolescents, so perhaps not generalisable to the wider population.
ATTITUDES - Wegner et al (2002)
Students were asked to record eating patterns and mood states over a period of two weeks. Binge days were characterised by low mood compared to non-binge, yet there was no difference before and after a binge.
- Self-report techniques may be unreliable.
- If the participants were in a lowered mood, they may have felt worse about their binge-eating and may have exaggerated more.
- Other research has also shown a drop in mood afterwards.
- Benefit, if any, is fleeting at best.
- Only students were used, who may have different eating patterns to the general population anyway.
ATTITUDES - Krebs-Smith et al (1995)
One of the strongest determinants of fruit and vegetable consumption among adults is the extent to which they ate fruit and vegetables as children, probably down to the parents.
- Attitudes to food are likely to be a result of more than social learning alone.
- May not have been implicated by parents; may be linked to a certain personality type.
- Memory of childhood is not always reliable.
- Social desirability bias - May have lied about fruit and vegetable consumption to make themselves look better.
EVOLUTIONARY - Milton (2008)
It is unlikely humans could have secured enough nutrition from a vegetarian diet to evolve into the active and intelligent creatures we became.
- The human digestive system has evolved to eat meat as the small size of the gastrointestinal tract helps with the digestion and absorption of protein.
- Reductionist - Food preference is shaped by culture.
- High fat and calories gives enough energy for hunting.
EVOLUTIONARY - Garcia et al (1955)
Rats made ill through radiation shortly after eating saccharin developed an aversion to it.
When a distinctive flavour is presented to a thiamine-deficient rat and then followed by an injection of thiamine, it acquires a preference for it.
- Rat physiology is different to humans, so may not be generalisable.
- Ethical issues - Causing harm to the rats.
- Supported by taste aversion during chemotherapy.
EVOLUTIONARY - Cordain et al (2006)
Argued our ancestors may have been healthy eaters and vegetarians.
- We would not have been able to get sufficient calories from the plants and grains available.
- Evidence shows all societies display a preference for animal fats and foods.
- Chimpanzees go for the fattiest part of prey after starvation.
EVOLUTIONARY - Sandell and Breslin (2006)
Screened 35 adults for the bitter taste receptor gene. Glucosinolates are toxic at high doses. Those with the sensitive form of the gene rated glucosinolate-containing vegetables as 60% more bitter than those with the insensitive form.
- This would have had a selective advantage on our ancestors. However, in that case, why does the insensitive form of the gene still exist?
- Ratings may not be accurate as they are self-reported and subjective.
NEURAL MECHANISMS - Wickens (2000)
When the neurotransmitter neuropeptide Y was injected into rats, they immediately began feeding.
- Ethical issues - Injections could have caused distress to the rats.
- Rat physiology is different to that of humans.
- Other research has shown that mice who didn't make NPY showed no decrease in feeding behaviour.
NEURAL MECHANISMS - Rolls and Rolls (1973)
Rats with no amygdala ate familiar and novel foods indiscriminately.
- Ethical issues - May have caused future danger to rats if they eat non-food items.
- Generalisability issues as rats and humans have different physiology.
NEURAL MECHANISMS - Kolb and Whishaw (2006)
Damage to the interior frontal cortex decreases eating due to diminished sensory responses to food odour, and therefore to taste.
- Kluver-Bucy Syndrome may be a result of damage to both the interior frontal cortex and the amygdala, leading to symptoms of indiscriminate eating.
- Hunger would still motivate someone to eat, despite the fact they couldn't taste it, so eating may not decrease.
NEURAL MECHANISMS - Lutter et al (2008)
The body produces extra ghrelin in response to stress, which boosts appetite.
- This explains comfort-eating.
- Comfort-eating or binge-eating does not boost mood, and may in fact induce more stress, leading to a vicious cycle.
- Real-world application - Obesity may be a result of stress.
DIETING - Ogden (2007) and Ashmore et al (2008)
Ogden (2007) - People diet to look better.
Ashmore et al (2008) - People diet for health reasons and to avoid prejudice and discrimination.
- Obtained through anecdotal evidence.
DIETING - Herman and Mack (1975)
Restraint theory suggests attempting not to eat increases chances of overeating. Dieters have a larger range between hunger and satiety as it takes longer to feel hungry and more food to satisfy them.
- Restricting anorexics' behaviour cannot be explained by restraint theory.
- Overeating may be a consequence rather than a cause of obesity if restraint is the recommended treatment.
DIETING - Redden (2003)
Gave 135 participants 22 jelly beans, one at a time. Those who were informed of the specific flavour every time enjoyed the task more.
- Real-world application - If the specific meals of a diet are concentrated on, it is more likely to be maintained.
- Fairly large sample size.
- Self-reported as to whether the task was enjoyed.
DIETING - Wegner (1994)
Participants who were told not to think about a 'white bear' were more likely to report that they had than those who were told that they must. This is called the 'theory of ironic processes of mental control'.
- Although the ironic effects were detectable they were not overwhelming.
- As soon as a food is denied, it simultaneously becomes more attractive.
- Real-world application - In this case, it may be more sensible to cut back on foods when dieting rather than removing them completely.
- Social desirability bias - Those who were told not to think about the 'white bear' may have said they had thought about it less than they actually had, in order to make themselves look more obedient. This may mean the effects were actually more prominent than reported.
DIETING - Higgins and Gray (1999)
Did a meta-analysis on programmes encouraging replacing dieting with healthy eating and found improvements in eating behaviour, psychological wellbeing and weight stability.
- Meta-analysis produces accurate results as it takes into account multiple studies.
- Real-world application - May be more effective than dieting. Also reduces side effects of dieting such as hunger and mood swings.
- However, may not be the best method for losing weight, only maintaining weight.
ANOREXIA PSYCHOLOGICAL - Hoek et al (1998)
Studied 44,192 patient records from a non-western Caribbean island and found 6 cases, which is within the range of Western countries.
- Large sample size.
- Accurate as they are officially clinically diagnosed.
- Perhaps cultural influences mean that Anorexia sufferers are more likely to report disordered eating in a specific culture, as it may be more accepted. Therefore, there may be more cases undiagnosed.
ANOREXIA PSYCHOLOGICAL - Becker et al (2002)
Following the introduction of TV in 1995, Fijian girls said they wanted to lose weight to be like the characters.
- Intervening prior to exposure to the media may reduce the damaging effects.
- Self-report techniques may have been influenced by demand characteristics.
- Focused on females, when males are also affected by eating disorders.
ANOREXIA PSYCHOLOGICAL - Grabe and Hyde (2006)
Meta-analysis of 98 studies found that African-Americans had significantly less body dissatisfaction than Caucasian and Hispanic females.
- This may be because the opposite sex value different body types, influenced by culture.
- A meta-analysis produces reliable results.
- Large sample of studies.
ANOREXIA PSYCHOLOGICAL - Lunde et al (2006)
A positive correlation was found between BMI and teasing in 10-year-old boys and girls.
- There is evidence supporting that underweight rather than overweight boys are most likely to be teased.
- Sensitive research with vulnerable participants.
- Correlation does not produce detailed research.
ANOREXIA PSYCHOLOGICAL - Bruch (1973)
Effective parents understand and respond to a child's needs. Ineffective parents produce children confused about their needs, who then gain excessive control over their body size.
- Evidence shows anorexics rely excessively on the opinions of others and feel a lack of control over their lives.
- Real-world application - Parents would feel guilty.
ANOREXIA PSYCHOLOGICAL - Strober et al (2006)
In people recieving treatment, 73% of girls and 50% of boys show signs of perfectionism.
- It is difficult to separate personality traits from short-lived states.
- Using clinically diagnosed samples produces a certain personality type.
- Proposes that there is a genetic vulnerability, as perfectionism runs in families.
ANOREXIA PSYCHOLOGICAL - Diuvuri and Kaye (2009)
Individuals with the binge-purge subtype display dyscontrol phenomena such as histories of self-harm, affective and behavioural disorder, substance abuse and overt family conflict in comparison to the restricting subtype.
- Certain personality type may contribute.
- Familly background may predict the subtype of Anorexia.
- Inability to control links to effective/ineffective parenting.
ANOREXIA BIOLOGICAL - Eagles et al (2001)
Found AN individuals are more likely to be born in the spring, possibly due to temperature and infections at time of conception.
- Constantly hot countries don't have this effect.
- In a spring baby, the second trimester occurs when infections are more likely, which is when brain development is most critical.
ANOREXIA BIOLOGICAL - Lindberg and Hjern (2003)
There is an association between premature birth and AN.
- This may be due to complications leading to hypoxia and then brain damage.
- It is suggested that poor nutrition can lead to premature birth. Therefore, mothers with AN may be more likely to produce children which develop AN, through genetic vulnerability AND inadequate nutrition.
ANOREXIA BIOLOGICAL - Kaye et al (2005)
PET scans showed overactive dopamine receptors in the basal ganglia in AN women.
- This alters the way that rewards are recieved. This could perhaps be applied to body distortion: even if a weight loss goal is reached, they continue to want to lose weight.
- They may struggle to accept compliments.
ANOREXIA BIOLOGICAL - Bailer et al (2007)
There was significantly higher serotonin activity in women recovering from the binge-eating/purging type than the restricting type. Highest serotonin levels were found in those with the most anxiety.
- SSRIs are ineffective in treating AN patients. However, this may be because malnutrition negates their effects.
- Gender bias - research only on women yet 25% of AN adults are men.
ANOREXIA BIOLOGICAL - Guisinger et al (2003)
The 'adapted to flee famine' hypothesis. Typical AN symptoms reflect the adaptive mechanisms that once caused migration in response to famine. Food restriction may occur when it competes with activities such as migrating or breeding. Hyperactivity may be a form of 'migratoty restlessness' where species are more confident in moving to somewhere 'favourable'.
- If this is a powerful biological urge, parents can learn to be more compassionate.
- Real-world appliaction - Finding a biological cause can influence treatment.
ANOREXIA BIOLOGICAL - Surbey (1987)
The reproduction suppression hypothesis. AN may be an effective way to delay reproduction when a female is stressed or in poor physical condition.
- Menarche is delayed in prepubertal girls with AN, and amenorrhea means reproduction is successfully suspended.
- Symptoms should not be passed on according to evolution as they decrease fertility and can even be fatal.
- An evolutionary explanation is reductionist and determinist.
ANOREXIA BIOLOGICAL - Holland et al (1984)
Looked at the concordance for AN in twins. Monozygotic = 55%. Dizygotic = 7%.
- Although this suggests a genetic link, it also supports the idea that particular personalities are more likely to develop AN.
- Twins are often born prematurely.