Psychological Explanations
Psychology: AQA A Level, topic 13.1.11
Psychological Explanations for Obesity
Herman and Polivy (1975) proposed restraint theory. The theory posits that the more an individual tries to restrain themselves from eating, the more they eat. The boundary model explains this phenomenon.
Restraint
- Restraint refers to an individual’s conscious effort to not consume food to avoid gaining weight or promote losing weight.
Restraint theory
- When people try to restrain themselves from eating too much, they implement a cognitive diet boundary.
- These eaters will eat until the cognitive boundary is reached, where they will then stop.
- But as they are still hungry, they will often eat beyond the boundary. Once this happens, they enter into a state of disinhibition.
The boundary model
- The boundary model posits that there is a biological continuum with hunger at the minimum and satiety at the maximum.
- Food intake is triggered when the minimum level is reached, hunger, and stops when the maximum level is reach, satiety.
- This process means that we always consume the minimum amount needed and so stay healthy.
- But many psychological, environmental and social factors can impact the size of the range, and so individuals can develop unhealthy eating behaviours.
Disinhibition
- If an individual who is trying to restrict their eating goes over their cognitive limit and enters disinhibition, they proceed to ‘give-up’ on their restriction and binge eat.
- This comes from the idea that if they have already broken their cognitive barrier, they may as well break it completely and eat until they are full, or beyond.
- This disinhibition may be triggered by specific emotional or situational factors, or just by habitual behaviours.
Cognitive control
- When food becomes a consuming part of our cognitive life, we can end up ignoring physiological markers of hunger and satiety and instead try to control our food intake consciously.
- Cognitive factors tend to control restrained eaters, while physiological factors control normal eaters.
Test yourself on Psychological Explanations
What is the maximum level along the continuum in the boundary model?
Which model suggests that there is a biological continuum between hunger and satiety?