Assortative Mating for Cigarette Smoking and for Alcohol Consumption in Female Australian Twins and their Spouses

Background Non-random mating affects population variation for substance use and dependence. Developmentally, mate selection leading to positive spousal correlations for genetic similarity may result in increased risk for substance use and misuse in offspring. Mate selection varies by cohort and thus, assortative mating in one generation may produce marked changes in rates of substance use in the next. We aim to clarify the mechanisms contributing to spousal similarity for cigarette smoking and alcohol consumption. Methods Using data from female twins and their male spouses, we fit univariate and bivariate twin models to examine the contribution of primary assortative mating and reciprocal marital interaction to spousal resemblance for regular cigarette smoking and nicotine dependence, and for regular alcohol use and alcohol dependence. Results We found that assortative mating significantly influenced regular smoking, regular alcohol use, nicotine dependence and alcohol dependence. The bivariate models for cigarette smoking and alcohol consumption also highlighted the importance of primary assortative mating on all stages of cigarette smoking and alcohol consumption, with additional evidence for assortative mating across the two stages of alcohol consumption. Conclusions Women who regularly used, and subsequently were dependent on cigarettes or alcohol were more likely to marry men with similar behaviors. After mate selection had occurred, one partner's cigarette or alcohol involvement did not significantly modify the other partner's involvement with these psychoactive substances.

The implications of simultaneous smoking initiation for inferences about the genetics of smoking behavior from twin data

We examined early social influences across stages of smoking within the context of a twin study using an environmental exposure specific to smoking: whether twins started smoking at the same time (simultaneous smoking initiation: SSI). We expected that SSI would be a good index of shared social influences on smoking initiation. Rates of SSI were indeed significantly higher in MZ twins and in twins who shared peers and classes, as well as in male twins. With the exception of regular smoking in females, we found no significant difference in estimates of genetic and environmental parameters between SSI and non-SSI pairs for any of the smoking measures that we examined (DSM-IV and Fagerstrom HSI measures of nicotine dependence; DSM-IV nicotine withdrawal; heavy smoking; and in males, regular smoking). For regular smoking in females, allowing for additional shared environmental influences associated with SSI only modestly reduced our estimates of additive genetic variance (56% vs. 68%). These results indicate the important social influences that may occur for smoking initiation do not appear to seriously bias estimates of genetic effects on later stages of smoking.

Social support and postpartum depressive symptomatology: The mediating role of maternal self-efficacy

Research shows that social support and maternal self-efficacy are inversely related to postpartum depression; however, little is known about the mechanisms by which these variables impact on depressive symptomatology. This study uses path analysis to examine the proposal that maternal self-efficacy mediates the effects of social support on postpartum depressive symptomatology. Primiparous women (n=247) completed questionnaires during their last trimester and then again at 4 weeks' postpartum (n=192). It was hypothesized that higher levels of parental support, partner support, and maternal self-efficacy would be associated with lower levels of depressive symptomatology postpartum and that the relationship between social support and depressive symptomatology would be mediated by maternal self-efficacy. Results indicated that as expected, higher parental support and maternal self-efficacy were associated with lower levels of depressive symptomatology postpartum. Partner support was found to be unrelated to both depressive symptomatology and maternal self-efficacy. Results from the path analysis supported the mediation model. Findings suggest that parental support lowers depressive symptomatology by the enhancement of maternal self-efficacy.

Mental playmates: Siblings, executive functioning and theory of mind

This study assessed the theory of mind (ToM) and executive functioning (EF) abilities of 124 typically developing preschool children aged 3 to 5 years in relation to whether or not they had a child-aged sibling (i.e. a child aged 1 to 12 years) at home with whom to play and converse. On a ToM battery that included tests of false belief, appearance-reality (AR) and pretend representation, children who had at least 1 child-aged sibling scored significantly higher than both only children and those whose only siblings were infants or adults. The numbers of child-aged siblings in preschoolers' families positively predicted their scores on both a ToM battery (4 tasks) and an EF battery (2 tasks), and these associations remained significant with language ability partialled out. Results of a hierarchical multiple regression analysis revealed that independent contributions to individual differences in ToM were made by language ability, EF skill and having a child-aged sibling. However, even though some conditions for mediation were met, there was no statistically reliable evidence that EF skills mediated the advantage of presence of child-aged siblings for ToM performance. While consistent with the theory that distinctively childish interaction among siblings accelerates the growth of both TOM and EF capacities, alternative evidence and alternative theoretical interpretations for the findings were also considered.

Screening for anxiety in mild cognitvely impaired individuals

Anxiety disorders are one of the most common psychiatric complaints across aU age cohorts, including older adults over age 65 (Regier et al., 1988; Regier, Narrow & Rae, 1990). Despite being a common complaint among older adults, anxiety remains underreported by patients and under diagnosed by health professionals (Stanley & Beck, 2000). Anxiety disorders have been less well studied in older adults than depression, both in terms of the assessment as well as treatment. While several anxiet)' inventories have normative data available for older populations, few anxiet)' measures have been specifically designed to be used with older populations. The primar)' aim of this pilot project was to evaluate the utility of a new anxiety screen specifically designed for older adults, the Geriatric Anxiet)' Inventor)' (GAI) on an older cohort with mild cognitive deficits.

Do economists ‘compose’ economics? A comparison of the creative processes of artists and economists

This is a draft for a chapter of the book version of my Ph.D thesis. The chapter addresses the following question: Are the creative processes of musical composers and academic economists essentially the same, or are there significant differences? The paper finds that there are deep similarities between the creative processes of theoretical economists and the creative processes of artists. The chapter builds a process oriented lifecycle account of creative activity, drawing on testimonial material from the arts and the sciences, and relates the model to the creative work of economists developing economic theory.

Psychological science in Australia

This paper is a brief account of the Australian Strategic Review of the Psychology Discipline and its Research. Issues discussed include Australia's contribution to world research in psychological science, research funding, the age and qualifications of researchers, the social and economic benefits arising from the applications of research outcomes, multidisciplinary issues, the role of psychology in industry, links between the discipline and the profession of psychology, professional training, cross-cultural issues, and educational issues. Priorities for development of research and postgraduate training are identified, and include human factors and other areas related to technological change, clinical psychology with particular attention to health psychology, industrial and organizational psychology, and neuroscience and physiological psychology.

Advice on exercise from a family physician can help sedentary patients to become active

Objectives: To test the effectiveness, in the setting of primary health care, of verbal advice on exercise from a family physician (FP) combined with supporting written information. Design: A controlled trial with subjects allocated to a control group or one of two intervention groups using a balanced design based on day of the week. Setting: Ten general practices in Perth, Western Australia. Subjects: All sedentary patients consulting an FP. Intervention: Verbal advice on exercise from the FP and a pamphlet on exercise mailed to the patient's home address within 2 days of his/her visit to the doctor. Main outcome measure: Level of physical activity at followup. Results: 6,351 adult patients attending an FP practice completed a screening questionnaire, and 763 sedentary adults were recruited to the project. The response to follow-up, via a postal survey at 1, 6, and 12 months after the index consultation was 70%, 60%, and 57%, respectively. At 1 month a subsample of the control and intervention subjects were contacted for a telephone interview to verify self-reported levels of activity (n = 136). Treating all nonresponders as sedentary, at 1 month significantly more subjects in the combined intervention groups reported doing some physical activity (40%) compared with the control group (31%). Similarly, at 6 months, 30% of the control group and 38% of the combined intervention groups were now active. There was very little change at followup at 12 months (31% control and 36% intervention groups, respectively). Conclusion: A simple intervention aimed at the promotion of physical activity to sedentary patients in general practice can help reduce inactivity.

Insufficiently active Australian college students: Perceived personal, social, and environmental influences

Background. A sustainable pattern of participation in physical activity is important in the maintenance of health and prevention of disease, College students are in transition from an active youth to a more sedentary adult behavior pattern. Methods. We assessed self-reported physical activity and other characteristics in a sample of 2,729 male and female students (median age was 20 years) recruited from representative courses and year levels at four Australian College campuses. They were categorized as sufficiently or insufficiently active, using estimates of energy expenditure (kcal/week) derived from self-reported physical activity, Personal factors (self-efficacy, job status, enjoyment), social factors (social support from family/friends), and environmental factors (awareness of facilities, gym membership) were also assessed. Results. Forty-seven percent of females and 32% of males were insufficiently active. For females, the significant independent predictors of being insufficiently active were lower social support from family and friends, lower enjoyment of activity, and not working. For males, predictors were lower social support from family and friends, lower enjoyment of activity, and being older. Conclusions. Factors associated with physical activity participation (particularly social support from family and friends) can inform physical activity strategies directed at young adults in the college setting. (C) 1999 American Health Foundation and Academic Press.

Tailored advice on exercise - Does it make a difference?

Objectives: A controlled trial to compare the effectiveness of verbal advice from a family physician (FP) combined with either standard or tailored written information on physical activity in increasing the levels of physical activity in sedentary patients. Design: Sedentary patients (n = 763) were recruited through ten family practices and allocated to a control group or one of two intervention groups, Brief advice on physical activity was given by the FP during the consultation and either a standard or tailored pamphlet was mailed to the home address of patients assigned to the intervention groups within two days of their visit to the FP. Results: The response to follow-up, via a postal survey at one, six, and twelve months after the index consultation was 70%, 60%, and 57%, respectively. Treating all nonresponders as sedentary, the results revealed that although more tailored subjects reported some physical activity at each follow-up compared with the standard group, these differences were not significant, Furthermore, there was no significant difference in movement across the stages of readiness to exercise at follow-up between subjects in the tailored group who received material targeting their current stage (precontemplation or contemplation) and the standard group who received generic material that addressed both stages. Conclusion: These findings do not concur with the results from previous research in the areas of nutrition and smoking cessation where additional benefits were seen with a tailored intervention. Future research on the application of the principles of tailoring to the promotion of physical activity should focus on identifying which, if any, physical, social, psychological or environmental variables should be addressed to produce improved outcomes over and above the effects of well designed generic materials. (C) 1999 American Journal of Preventive Medicine.

Social-cognitive and perceived environment influences associated with physical activity in older Australians

Background, Regular physical activity in older adults can facilitate healthy aging, improve functional capacity, and prevent disease. However, factors associated with physical inactivity in older populations are poorly understood. This study attempts to identify social-cognitive and perceived environmental influences associated with physical activity participation in older populations. Methods. In a randomly selected sample of 449 Australian adults age 60 and older, we assessed self-reported physical activity and a range of social-cognitive and perceived environmental factors. Respondents were classified as sufficiently active and inactive based on energy expenditure estimates (kcal/week) derived from self-reported physical activity. Two logistic regression models, with and without self-efficacy included, were conducted to identify modifiable independent predictors of physical activity. Results. Significantly more males than females were physically active. Physical activity participation was related to age with a greater proportion of those age 65-69 being active than those age 60-64 or 70 or older. High self-efficacy, regular participation of friends and family, finding footpaths safe for walking, and access to local facilities were significantly associated with being active. Conclusion. Identifying predictors of physical activity in older populations, particularly social support, facility access, and neighbourhood safety, can inform the development of policy and intervention strategies to promote the health of older people. (C) 2000 American Health Foundation and Academic Press.

Occupation, hours worked, and leisure-time physical activity

Background. International research indicates that blue-collar employees typically exhibit lower rates of leisure-time physical activity. While lack of time and work demands are commonly reported barriers to activity, the extent to which time-at-work mediates the relationship between occupation and leisure-time physical activity is unclear. This study investigated the association between occupation, time spent in paid employment, and participation in leisure-time physical activity. Methods. This was a secondary analysis of cross-sectional data from the 1995 Australian Health Survey, focusing on employed persons ages 18-64 years (n = 24,454), Occupation was coded as per the Australian Standard Classification of Occupations and collapsed into three categories (professional, white-collar, blue-collar). Hours worked was categorized into eight levels, ranging from 1-14 to more than 50 h per week. Participation in leisure-time physical activity was categorized as either insufficient or sufficient for health, consistent with recommended levels of energy expenditure (1600 METS-min/fortnight). The relationship between occupation, hours worked, and leisure-time physical activity was examined using logistic regression. Analyses were conducted separately for male and female, and the results are presented as a series of models that successively adjust for a range of potential covariates: age, living arrangement, smoking status, body mass index, and self-reported health. Results. Individuals in blue-collar occupations were approximately 50% more likely to be classified as insufficiently active. This occupational variability in leisure-time physical activity was not explained by hours worked. There was a suggested relationship between hours worked and leisure-time physical activity; however, this differed between men and women, and was difficult to interpret. Conclusions. Occupational variability in leisure-time physical activity cannot be explained by hours worked. Therefore, reports that work constitutes a barrier to participation should be explored further. Identification of the factors contributing to occupational variability in leisure-time physical activity will add to our understanding of why population subgroups differ in their health risk profiles, and assist in the development of health promotion strategies to reduce rates of sedentariness and health inequalities. (C) 2000 American Health Foundation and Academic Press.