Application Studies

Weinstein (1983)

• Aim: To investigate the prevalence and characteristics of unrealistic optimism about future life events.

• Procedure: Conducted a series of questionnaire studies with university students. Participants were asked to compare their own chances of experiencing 42 different positive and negative life events (e.g., "being injured in a car accident," "developing lung cancer") to the chances of their peers.

• Results: The findings showed a strong and consistent trend of unrealistic optimism. Most participants believed they were far less likely than their peers to experience negative life events and more likely to experience positive ones. This bias was stronger for events perceived as controllable.

Johnston & White (2003)

• Aim: To test the Theory of Planned Behaviour (TPB) as a predictor of binge drinking intentions and behaviour among university students.

• Procedure: Students completed questionnaires measuring the components of the TPB: their attitudes toward binge drinking, subjective norms (perceived social pressure), perceived behavioural control (ease/difficulty of performing the behaviour), and their intentions to binge drink. Their self-reported binge drinking behaviour was measured at a later time.

• Results: Attitudes and perceived behavioural control were significant predictors of intentions to binge drink. Intentions, in turn, were a strong predictor of actual binge drinking behaviour.

Alexander et al. (1981)

• Aim: To investigate the role of environment and social isolation in morphine addiction in rats.

• Procedure: Rats were housed in one of two environments: isolated cages or a large, enriched colony ("Rat Park") with other rats, space, and toys. All rats were given continuous access to both plain water and morphine-laced water.

• Results: The isolated rats consumed significantly more morphine solution than the rats in Rat Park. The social rats in Rat Park strongly preferred plain water, even if they had been forced to consume morphine previously

Kendler et al. (1997)

• Aim: To determine the relative impact of genetic and environmental factors on major depression in women.

• Procedure: A longitudinal study using a large US twin registry. Over 1,000 female twin pairs (both identical and fraternal) were interviewed on two occasions to assess for major depression, based on standardized diagnostic criteria.

• Results: Genetic factors accounted for approximately 33-45% of the risk for major depression. Individual-specific environmental experiences (e.g., personal life events) accounted for most of the remaining variance, while the shared family environment had a minimal effect.

Witte & Allen (2000)

• Aim: To test the Extended Parallel Process Model (EPPM) by examining when fear appeals in health promotion are effective or lead to defensive reactions.

• Procedure: Conducted a meta-analysis of previous fear appeal studies and a series of new experiments. Participants were exposed to health messages (e.g., about HIV, tetanus) that varied in their level of fear (high vs. low) and the efficacy of the recommended response (high vs. low).

• Results: Fear appeals were only effective when paired with high-efficacy messages (i.e., when people were told about a serious threat and given a feasible, effective solution). High-fear messages with low-efficacy information led to defensive avoidance and rejection of the message.

Janis & Feshbach (1953)

• Aim: To investigate the effects of different levels of fear arousal on the effectiveness of a health education message.

• Procedure: High school students were divided into three groups. Each group received a lecture on dental hygiene with varying levels of fear arousal: Strong Fear (graphic images of tooth decay), Moderate Fear, and Minimal Fear. Their dental hygiene practices and attitudes were measured before and after the lectures.

• Results: The Minimal Fear group showed the greatest positive change in dental hygiene behaviour. The Strong Fear group showed the least change and reported more feelings of denial and rejection of the message.

Marmot et al. (1997)

• Aim: To investigate the social determinants of health, specifically the relationship between employment grade, stress, and the incidence of coronary heart disease (CHD) and other health outcomes.

• Procedure: A prospective longitudinal study of over 10,000 British civil servants. Participants' employment grade, psychosocial factors (e.g., job control, social support), health behaviours, and morbidity were tracked over time.

• Results: There was a strong, inverse social gradient in health: lower employment grade was associated with a higher incidence of CHD and poorer overall health. This relationship was partially explained by lower job control and higher job stress reported by those in lower grades.

Felitti et al. (1998)

• Aim: To examine the relationship between adverse childhood experiences (ACEs) and adult health and well-being.

• Procedure: Over 9,500 participants completed a standardized medical examination and a confidential survey about their childhood experiences (e.g., abuse, neglect, household dysfunction) and current health status.

• Results: A strong, graded relationship was found between the number of ACEs and the risk of adult health problems, including heart disease, cancer, chronic lung disease, depression, and addiction. The more ACEs a person experienced, the higher their risk.