Brett Holfeld

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The relationship between sleep quality and physical activity is bidirectional, yet prior research on older adults has mainly focused on investigating whether increasing levels of physical activity leads to improvements in sleep quality. The current longitudinal study examined both directional relationships by assessing sleep quality and physical activity(More)
Bystanders play a critical role in the maintenance or reduction of bullying behavior. The potentially unlimited audience in the online world suggests that the role of bystanders may be particularly important in cyber bullying. However, little is known about the perceptions of bystanders or the situational factors that can increase or decrease their support(More)
Pressure for 'positive thinking' (PT; i.e., focusing on positive thoughts/suppressing negative thoughts to 'fight' cancer) burdens cancer patients facing health deterioration. It was determined whether PT exposure enhanced effort, control and responsibility attributions assigned to an individual for his/her cancer trajectory. Within an online blog a(More)
OBJECTIVE We examine concurrent and longitudinal associations between sleep duration (SD) and body mass index (BMI) from adolescence to young adulthood, controlling for physical activity and internalising symptoms. Sex and age group differences (early adolescent group ages 12-15 years and late adolescent group ages 16-18 years) are examined. DESIGN A(More)
Positive thinking (PT; i.e., sustaining positive thoughts and suppressing negative thoughts to "fight" cancer) is often equated with direct control over one's cancer trajectory. It was determined whether PT exposure enhanced the effort, control, and responsibility attributions ascribed to a peer for his/her cancer trajectory, and whether those ascriptions(More)
Past research suggests that exposure to parent psychological control and peer relational aggression and victimization experienced during adolescence is associated with relational intimate partner violence (IPV) in young adults (ages 22 to 29). However, the effects of continuities in these concerns across young adulthood have not been assessed. Relational(More)
With increasing frequency of Internet use among adolescents, there are growing concerns about their risk for becoming attached to these forms of communication and increased vulnerability for negative online experiences, including cyber victimization. The effect of these experiences on adolescent mental health is not well understood. In this study, we(More)
We investigated whether the Interview-Identification-Eyewitness factors (I-I-Eye) educational aid could sensitize mock jurors to the quality of eyewitness evidence in criminal cases which also contained circumstantial and forensic evidence. After participants were randomly assigned to read either the I-I-Eye or a control aid, they read a trial transcript(More)
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