title: Psychometric properties of optimism and pessimism: results from the Girls' Health Enrichment Multisite Studies.
abstract: Background. This study investigated the relationships among optimism, pessimism, physical activity, and dietary behaviors among 8- to 10-year-old African-American girls in the Girls' Health Enrichment Multisite Studies (GEMS). Methods. Ninety-two girls were randomly assigned to a 12-week physical activity and diet intervention or comparison group and completed psychosocial assessments including the Youth Life Orientation Test (YLOT) of optimism and pessimism, physical performance self-concept, physical activity self-efficacy, physical activity outcome expectancies, and physical activity and sedentary preferences. Also, preferences for bottled water and sweetened beverages were assessed. Physical activity and dietary intake were assessed by self-report and parent-report at baseline and follow-up. Also, physical activity was objectively assessed by wearing an accelerometer for 3 days. The psychometric properties of the optimism-pessimism subscales were analyzed. Results. The measures of optimism and pessimism in children were reliable (r = 0.75-0.82). In the multiple regression analyses without the intervention interaction terms, pessimism was positively and significantly related to increases in MET-adjusted usual activity (P = 0.008) and sedentary behaviors (P = 0.0004). Additionally, a negative (P = 0.026) pessimism by intervention interaction term for MET-adjusted usual activity was found such that the intervention group had a lower change in physical activity per unit increase in pessimism compared to the control group.
  
  
  CONCLUSIONS
  Among 8- to 10-year-old African-American girls, pessimism was related to increased sedentary behaviors and usual activity. Previous studies have reported relationships between optimism and health-compromising behaviors. This study found that pessimism may positively or negatively influence efforts to increase health-promoting behaviors. Future research should confirm and clarify the meaning of these findings.
authors.affiliation: Center for Health Promotion and Prevention Research (CHPPR), School of Public Health, University of Texas Health Science Center at Houston, 77030, USA. wtaylor@sph.uth.tmc.edu
authors.forename: Wendell C
authors.initials: WC
authors.lastname: Taylor
authors.forename: Tom
authors.initials: T
authors.lastname: Baranowski
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Klesges
authors.forename: Sydney
authors.initials: S
authors.lastname: Ey
authors.forename: Charlotte
authors.initials: C
authors.lastname: Pratt
authors.forename: Jim
authors.initials: J
authors.lastname: Rochon
authors.forename: Ainong
authors.initials: A
authors.lastname: Zhou
mesh_terms: D001741:Black or African American / Q000523:psychology; D002648:Child; D015444:Exercise / Q000523:psychology*; D005247:Feeding Behavior / Q000523:psychology*; D005260:Female; D006801:Humans; D016014:Linear Models; D015337:Multicenter Studies as Topic / Q000706:statistics & numerical data; D015999:Multivariate Analysis; D009765:Obesity / Q000517:prevention & control* / Q000523:psychology; D010551:Personality; D011581:Psychological Tests; D011594:Psychometrics; D016032:Randomized Controlled Trials as Topic / Q000706:statistics & numerical data; D015203:Reproducibility of Results; D014481:United States