Publications

Comparing twins from same- and opposite-sex pairs can provide information on potential sex differences in a variety of outcomes, including socioeconomic-related outcomes such as educational attainment. It has been suggested that this design can be applied to examine the putative role of intrauterine exposure to testosterone for educational attainment, but the evidence is still disputed. […]

Background: Neuroimaging studies suggest that appetitive drive is enhanced in obesity. Objective: To test if appetitive drive varies in direct proportion to the level of body adiposity after accounting for genetic factors that contribute to both brain response and obesity risk. Subjects/Methods: Participants were adult monozygotic (n=54) and dizygotic (n=30) twins with at least one […]

The COVID-19 pandemic and resulting lockdowns have had a disproportionate impact on parents of children under 18, particularly women. Mandatory school closures and loss of childcare resulted in parents balancing work, teaching, and childcare needs. A number of studies have examined changes in mental health of parents, but to date no studies have compared the […]

Studies often rely on home locations to access built environment (BE) influences on physical activity (PA). We use GPS and accelerometer data collected for 288 individuals over a two-week period to examine eight GPS-derived BE characteristics and moderate-to-vigorous PA (MVPA) and light-to-moderate-vigorous PA (LMVPA). NDVI, parks, blue space, pedestrian-orientated intersections, and population density were associated […]

This study examined how buffer type (shape), size, and the allocation of activity bouts inside buffers that delineate the neighborhood spatially produce different estimates of neighborhood-based physical activity. A sample of 375 adults wore a global positioning system (GPS) data logger and accelerometer over 2 weeks under free-living conditions. Analytically, the amount of neighborhood physical […]

Posttraumatic stress disorder (PTSD) and eating disorders (ED) frequently co-occur, but the mechanisms underlying this association remain unclear. EDs are characterized by features of maladaptive eating behaviors including disinhibited eating and cognitive dietary restraint. Identifying the genetic overlap between PTSD symptoms and maladaptive eating behaviors may elucidate biological mechanisms and potential treatment targets. A community […]

In response to the COVID-19 pandemic, a variety of social distancing measures to mitigate the virus outbreak have been implemented. These measures may have unintended consequences on individuals’ well-being, such as increased stress, anxiety, and sleep disruptions. We investigated the extent to which individuals’ mental health status is associated with perceived changes in sleep amount […]

Millions of people have been impacted by the novel coronavirus (COVID-19) pandemic worldwide. High infection rates and death tolls, combined with social distancing measures, may have unintended psychological consequences on individuals. The goal of this study was to examine the interrelations between COVID-19 exposure, fear of COVID-19, and depression among a community-based sample of adult […]

Background Context: LBP is a common and significant cause of disability worldwide, however; questions about cause still remain. Purpose: To investigate the association between low back pain (LBP), body mass index (BMI), and moderate to vigorous physical activity (MVPA) in a twin sample. Study Design: Cross sectional study of monozygotic (MZ) and dizygotic (DZ) twins […]

The novel coronavirus (COVID-19) has impacted the lives of people worldwide since being declared a pandemic on March 11, 2020. Social restrictions aimed at flattening the curve may be associated with an increase in stress and anxiety, which may increase the use of alcohol as a coping mechanism. The objective of this study was to […]

Background: Evidence suggests that depression and anxiety disorders are genetically based. Although symptoms of these internalizing disorders tend to correlate, the degree to which the related symptoms are heritable is unclear. This overlap has been conceptualized as Anxious Misery and existing research examining similar constructs of negative affect has revealed moderate heritability. However, it is […]

Background: Physical distancing and other COVID-19 pandemic mitigation strategies may have unintended consequences on a number of health behaviors and health outcomes. The purpose of this study was to investigate the association between perceived change in physical activity or exercise and mental health outcomes over the short-term in response to COVID-19 mitigation strategies in a […]

We examined the item properties of the Two Peas Questionnaire (TPQ) among a sample of same-sex twin pairs from the Washington State Twin Registry. With the exception of the ‘two peas’ item, three of the mistakenness items showed differential item functioning. Results showed that the monozygotic (MZ) and dizygotic (DZ) pairs may differ in their […]

We investigated the heritability of educational attainment and how it differed between birth cohorts and cultural-geographic regions. A classical twin design was applied to pooled data from 28 cohorts representing 16 countries and including 193,518 twins with information on educational attainment at 25 years of age or older. Genetic factors explained the major part of […]

The pervasive, damaging nature of posttraumatic stress disorder (PTSD) presents enormous clinical challenges. Understanding the relationship between patients’ perceptions of PTSD symptoms and resilient coping strategies may prompt investigation of clinical interventions that improve adaptive, resilient coping skills. In this study, we examined whether changes in resilient coping were related to changes over time in […]

Using a twin study design, we explored the extent to which affectionate communication is a heritable behavioral trait. Participants (N = 928) were 464 adult twin pairs (229 monozygotic, 235 dizygotic) who provided data on their affectionate communication behaviors. Through ACE modeling, we determined that approximately 45% of the variance in trait expressed affectionate communication is heritable, whereas 21% […]

Background: There has been increased interest in the interplay of genetic and environmental factors in the development of problematic alcohol use, including socioeconomic conditions of the neighborhood. Using a co-twin design, we examined the extent to which contributions of genetic, shared environmental, and unique environmental influences on hazardous drinking differed according to levels of neighborhood […]

Asthma is the most prevalent chronic lung inflammatory disorder characterized by reversible airflow obstruction, affecting 358 million people worldwide, with aggravating factors like obesity, attention‐deficit/hyperactivity disorder, socioeconomic status like poor healthcare affordability and facility, smoking and alcohol intake. RNA sequencing (RNA‐seq) in atopic asthma, childhood asthma and adult‐onset severe asthma has improved our understanding of cellular and […]

Posttraumatic stress disorder (PTSD) and insomnia are comorbid clinical conditions that are thought to result from genetic and environmental effects. Though studies have established the heritability of these disorders independently, no study to date has examined the genetic contributions to the relation between insomnia and PTSD symptoms (PTSS). The present study assessed this gap in […]

Background and objectives: The purpose of this project is to evaluate the association between twin sex discordance and menstrual characteristics. We hypothesize that sharing the uterus with a male twin can change ovulation programming, hence changing the menstrual cycle characteristics during adulthood. This project could be novel in discovering new physiological mechanisms of hormone exposure […]