Dynamic Associations Among Sleep, Emotion Dysregulation, and Desire to Live in a Perinatal Sample.

OBJECTIVE: The present study prospectively examined dynamic associations among sleep, emotion dysregulation, and desire to live during the perinatal transition, as it was theorized that these factors may contribute to the emergence of postpartum suicide risk. METHOD: Ninety-four women ( Mage = 29.2 years; 23.4% Latina) wore wrist actigraphs and completed twice daily surveys for 7 days during the third trimester of pregnancy, 6 weeks postpartum, and 4 months postpartum. Multilevel, change-as-outcome models were built to examine changes in attractor dynamics among sleep, emotion dysregulation, and desire to live, as well as if sleep-emotion dysregulation dynamics differed based on participants' desires to live. RESULTS: From pregnancy to 6 weeks postpartum, emotion dysregulation ( B = -0.09, p = .032) and desire to live ( B = -0.16, p < .001) exhibited more stable temporal patterns around higher emotion dysregulation and lower desire to live. Compared to women who reported consistently high desires to live, those who experienced fluctuations in their desires to live exhibited lower, more stable sleep efficiency during pregnancy ( B = -0.90, p < .001). At 4 months postpartum, those with fluctuating desires to live exhibited a coupling dynamic whereby low sleep efficiency predicted increases in emotion dysregulation ( B = -0.16, p = .020). CONCLUSIONS: This study was the first to examine nonlinear dynamics among risk factors for postpartum suicide, which may be evident as early as pregnancy and 6 weeks postpartum. Sleep health, in particular, warrants further exploration as a key susceptibility factor in the emergence of postpartum suicide risk. PREREGISTRATION: Open Science Framework ( https://osf.io/qxb75/?view_only=799ffe5c048842dfb89d3ddfebaa420d ).

Global stress and daily general and type 1 diabetes stressors and links to daily affect and diabetes outcomes during emerging adulthood.

We examined how global stress and general stressors of daily life relate to emotional well-being and type 1 diabetes (T1D) outcomes and amplify the effects of diabetes stressors in emerging adults. Two-hundred and seven 18-19-year-olds with T1D (duration 8.47 years) completed the Perceived Stress Scale (global stress) and a daily diary assessing daily diabetes and general stressors, positive and negative affect, self-care behaviors, and blood glucose (BG). Multi-level analyses indicated that global stress and within-person daily general and diabetes stressors were associated with more negative and less positive affect. In addition, general stress (between-person) was associated with more negative affect. Global stress amplified the association between daily diabetes stressors and negative affect, with greater affect reactivity to stress for those experiencing higher global stress. Global stress and both within- and between-person diabetes stressors were associated with lower self-care and higher BG. Emerging adults' general stressors in their daily lives relate to poorer well-being beyond the experience of diabetes stressors.

Executive Functioning, Daily Self-Regulation, and Diabetes Management while Transitioning into Emerging Adulthood.

BACKGROUND: Executive functioning (EF) predicts better Type 1 diabetes (T1D) management in the high-risk years after high school, but the daily self-regulation processes involved are unclear. PURPOSE: To examine whether EF is associated with daily self-regulation that minimizes one's exposure or buffers adverse reactions to daily diabetes problems, and to determine whether these patterns become stronger during the transition out of high school. METHODS: A measurement burst design with convenience sampling was used. Seniors in high school with T1D (N = 207; 66% female) completed self-report (i.e., Behavioral Rating Inventory of Executive Functioning) and performance measures of EF (i.e., Delis-Kaplan Executive Function System). A 14-day daily diary assessing self-regulation failures, diabetes problems, affect, and indicators of diabetes management was completed at baseline and 1 year later. RESULTS: Correlations and multilevel modeling were conducted. Lower self-reported EF problems were associated with lower average levels of daily self-regulation failures, and these variables were associated with fewer daily diabetes problems. In contrast, better EF performance was unrelated to average daily self-regulation failures, and was unexpectedly associated with more frequent diabetes problems in year 2. Equally across years, on days participants reported lower than their average levels of daily self-regulation failures, they had fewer diabetes problems, regardless of EF. On days with lower than average diabetes problems, participants reported better diabetes management indicators. EF generally did not buffer daily associations in either year. CONCLUSIONS: Regardless of EF, promoting daily self-regulation may prevent diabetes problems and promote T1D management in daily life at this high-risk transitional time.

Type 1 diabetes (T1D) requires daily self-regulation (e.g., remembering to check blood glucose; regulating emotions, thoughts, and behaviors when diabetes problems arise). These processes draw on executive function (EF) abilities, which may be challenged after high school, when youth experience many life transitions while managing diabetes more independently from parents. The study examined how EF is associated with daily diabetes management as youth transition out of high school. Seniors in high school with T1D completed measures of EF and two 14-day daily diaries, one in the senior year and one the following year. Each evening, participants completed an online survey reporting on self-regulation failures (e.g., forgetting to test blood glucose), diabetes problems, and diabetes management over the past 24 hr. Those with better self-reported EF had lower self-regulation failures and fewer diabetes problems on average. On days with lower self-regulation failures, participants had fewer diabetes problems. On days with fewer diabetes problems, participants reported lower negative emotions, higher confidence in diabetes management, and better self-care behaviors and blood glucose levels. These daily associations occurred regardless of EF. Providing youth with training in self-regulation to prevent daily diabetes problems may promote T1D management during this high-risk transition.

Parental Relationships, Patient-Centered Communication With Healthcare Providers, and Diabetes Management Across Emerging Adulthood.

OBJECTIVE: To examine whether yearly fluctuations in acceptance from and disclosure to parents were associated with fluctuations in perceptions of patient-centered communication (PCC) with the healthcare provider and whether fluctuations in PCC were associated with self-efficacy, type 1 diabetes self-care, and HbA1c across four annual assessments during early emerging adulthood (EA). METHODS: A total of 228 high school seniors (M age = 17.76 years at time 1) reported on mothers' and fathers' acceptance and diabetes-related disclosure to parents, diabetes self-care, and PCC once per year for 4 years. HbA1c was collected from assay kits. RESULTS: Multilevel models revealed within-person associations such that in years when individuals reported greater maternal acceptance than their average, they reported higher PCC. In addition, between-person differences indicated that individuals who reported more maternal acceptance on average relative to others also perceived greater PCC. Similar associations were found for EAs' reports of fathers. No significant effects were found for disclosure to either mother or father. Yearly fluctuations in PCC were associated with self-efficacy such that in years when perceived PCC was higher, self-efficacy was higher. Between person-effects were found for self-efficacy, self-care, and HbA1c such that individuals who reported more PCC on average relative to others reported higher self-efficacy, better self-care, and lower HbA1c. CONCLUSIONS: Aspects of EA's relationships with parents fluctuate with perceptions of PCC with healthcare providers. Perceived PCC with the healthcare provider may be important in higher self-efficacy, diabetes self-care, and lower HbA1c across the early EA years.

Retention, engagement, and binge-eating outcomes: Evaluating feasibility of the Binge-Eating Genetics Initiative study.

OBJECTIVE: Using preliminary data from the Binge-Eating Genetics Initiative (BEGIN), we evaluated the feasibility of delivering an eating disorder digital app, Recovery Record, through smartphone and wearable technology for individuals with binge-type eating disorders. METHODS: Participants (n = 170; 96% female) between 18 and 45 years old with lived experience of binge-eating disorder or bulimia nervosa and current binge-eating episodes were recruited through the Recovery Record app. They were randomized into a Watch (first-generation Apple Watch + iPhone) or iPhone group; they engaged with the app over 30 days and completed baseline and endpoint surveys. Retention, engagement, and associations between severity of illness and engagement were evaluated. RESULTS: Significantly more participants in the Watch group completed the study (p = .045); this group had greater engagement than the iPhone group (p's < .05; pseudo-R2 McFadden effect size = .01-.34). Overall, binge-eating episodes, reported for the previous 28 days, were significantly reduced from baseline (mean = 12.3) to endpoint (mean = 6.4): most participants in the Watch (60%) and iPhone (66%) groups reported reduced binge-eating episodes from baseline to endpoint. There were no significant group differences across measures of binge eating. In the Watch group, participants with fewer episodes of binge eating at baseline were more engaged (p's < .05; pseudo-R2 McFadden  = .01-.02). Engagement did not significantly predict binge eating at endpoint nor change in binge-eating episodes from baseline to endpoint for both the Watch and iPhone groups. DISCUSSION: Using wearable technology alongside iPhones to deliver an eating disorder app may improve study completion and app engagement compared with using iPhones alone.

The Binge Eating Genetics Initiative (BEGIN): study protocol.

BACKGROUND: The Binge Eating Genetics Initiative (BEGIN) is a multipronged investigation examining the interplay of genomic, gut microbiota, and behavioral factors in bulimia nervosa and binge-eating disorder. METHODS: 1000 individuals who meet current diagnostic criteria for bulimia nervosa or binge-eating disorder are being recruited to collect saliva samples for genotyping, fecal sampling for microbiota characterization, and recording of 30 days of passive data and behavioral phenotyping related to eating disorders using the app Recovery Record adapted for the Apple Watch. DISCUSSION: BEGIN examines the interplay of genomic, gut microbiota, and behavioral factors to explore etiology and develop predictors of risk, course of illness, and response to treatment in bulimia nervosa and binge-eating disorder. We will optimize the richness and longitudinal structure of deep passive and active phenotypic data to lay the foundation for a personalized precision medicine approach enabling just-in-time interventions that will allow individuals to disrupt eating disorder behaviors in real time before they occur. TRIAL REGISTRATION: The ClinicalTrials.gov identifier is NCT04162574. November 14, 2019, Retrospectively Registered.

The separation in coordination between social- and self-regulation for emerging adults with type 1 diabetes.

To examine how self-regulation and social-regulation surrounding type 1 diabetes (T1D) management are coordinated during early emerging adulthood and whether classes of coordination relate to HbA1c and executive functioning (EF). Emerging adult participants (N = 212) with T1D (M age = 18.8 years, SD = .40) completed a 14-day diary to capture components of self-regulation and social-regulation. A mixture multi-level latent coordination model first determined the separate but coordinated factor structure of self- and social-regulation, then determined the number of distinct classes of coordination and how those classes linked to HbA1c and EF. The best-fitting model included three coordinative factors (self, mother, and father) of regulation and two distinct classes. The class with lower HbA1c and higher EF had more stable self- and social-regulation, more connections between self- and social-regulation and reflected more adaptive patterns, consistent with medical management goals. Social connection with parents may aid in regulation during this at-risk transitional time of emerging adulthood.

Coregulation of therapist and client emotion during psychotherapy.

OBJECTIVE: Close interpersonal relationships are fundamental to emotion regulation. Clinical theory suggests that one role of therapists in psychotherapy is to help clients regulate emotions, however, if and how clients and therapists serve to regulate each other's emotions has not been empirically tested. Emotion coregulation - the bidirectional emotional linkage of two people that promotes emotional stability - is a specific, temporal process that provides a framework for testing the way in which therapists' and clients' emotions may be related on a moment to moment basis in clinically relevant ways. METHOD: Utilizing 227 audio recordings from a relationally oriented treatment (Motivational Interviewing), we estimated continuous values of vocally encoded emotional arousal via mean fundamental frequency. We used dynamic systems models to examine emotional coregulation, and tested the hypothesis that each individual's emotional arousal would be significantly associated with fluctuations in the other's emotional state over the course of a psychotherapy session. RESULTS: Results indicated that when clients became more emotionally labile over the course of the session, therapists became less so. When changes in therapist arousal increased, the client's tendency to become more aroused during session slowed. Alternatively, when changes in client arousal increased, the therapist's tendency to become less aroused slowed.

Nonlinear change processes and the emergence of suicidal behavior: a conceptual model based on the fluid vulnerability theory of suicide.

Although ideation-to-action theories of suicide aim to explain the emergence of suicidal behaviors, researchers have primarily focused on the content of underlying mechanisms (i.e., who dies by suicide). Much less attention has focused on the temporal dynamics of suicide risk (i.e., when suicide occurs). The fluid vulnerability theory conceptualizes suicide as an inherently dynamic construct that follows a nonlinear time course. Newer research implicates the existence of multiple nonlinear change processes among suicidal individuals, some of which appear to be associated with the emergence of suicidal behavior. The cusp catastrophe model provides a useful model for conceptualizing these change processes and provides a foundation for explaining a number of poorly understood phenomena including sudden emergence of suicidal behavior without prior suicidal planning. The implications of temporal dynamics for suicide-focused theory, practice, and research are discussed.

Parental Involvement and Executive Function in Emerging Adults with Type 1 Diabetes.

OBJECTIVE: To examine (a) changes in parental involvement across early emerging adulthood, (b) whether yearly fluctuations in parental involvement were associated with adherence and glycated hemoglobin (HbA1c) over time, and (c) whether higher involvement was more beneficial for those with poorer executive function (EF). METHODS: A total of 228 high school seniors (M age = 17.76) with type 1 diabetes reported on mothers' and fathers' acceptance, knowledge of diabetes activities, disclosure to mothers and fathers regarding diabetes, and adherence at four yearly time points. At baseline, participants completed performance-based measures of EF. HbA1c was collected from assay kits. RESULTS: Growth curve models revealed significant declines in disclosure to fathers and mothers' and fathers' knowledge of diabetes activities; no changes were found in mothers' or fathers' acceptance nor disclosure to mothers. Multilevel models indicated significant between-person effects for nearly all aspects of parental involvement with more acceptance, knowledge, and disclosure associated with better HbA1c and adherence. Within-person effects for disclosure to fathers, and mothers' and fathers' knowledge indicated that in years when emerging adults perceived higher amounts of these types of involvement (compared with their own average), HbA1c was lower. Within-person effects were found for acceptance to mothers, disclosure to mothers and fathers, and mothers' diabetes knowledge for adherence. Disclosure to fathers and mothers' knowledge of diabetes activities were especially beneficial for HbA1c for those with poorer EF performance. CONCLUSIONS: Parental involvement in diabetes management remains important during the high-risk time of emerging adulthood, especially for those with poorer EF.

Structural model of patient-centered communication and diabetes management in early emerging adults at the transfer to adult care.

Early emerging adulthood (ages 18-25) is a time of risk for type 1 diabetes (T1D) when relationships with parents and providers are changing. We examined whether individuals' high-quality relationships with mothers are associated with greater perceptions of patient-centered communication (PCC) with their doctor and whether PCC is associated with better adherence and glycemic control through diabetes-related self-efficacy. Additionally, we tested whether associations of PCC with self-efficacy and diabetes outcomes are stronger among those who had transferred to adult care. One-year post-high school, 217 individuals with T1D (60% women, 53% in adult care) reported perceptions of maternal relationship quality, PCC, self-efficacy, and adherence. Glycemic control was measured via HbA1c assay kits. Structural equation modeling indicated good model fit and revealed indirect paths linking higher maternal relationship quality to better adherence through higher PCC, and higher PCC to better HbA1c through adherence. Transfer status moderated the link between PCC and self-efficacy, suggesting PCC may be especially important when emerging adults transfer to adult care.

Coordination of Self- and Parental-Regulation Surrounding Type I Diabetes Management in Late Adolescence.

Background: Type 1 diabetes management involves self- and social-regulation, with past research examining components through individual differences unable to capture daily processes. Purpose: Dynamical systems modeling was used to examine the coordinative structure of self- and social-regulation (operationalized as parental-regulation) related to daily diabetes management during late adolescence. Methods: Two hundred and thirty-six late adolescents with type 1 diabetes (M age = 17.77 years, SD = .39) completed a 14-day diary reporting aspects of self- (e.g., adherence behaviors, cognitive self-regulation failures, and positive and negative affect) and parental-regulation (disclosure to parents, knowledge parents have, and help parents provide). Results: Self-regulation functioned as one coordinative structure that was separate from parental-regulation, where mothers and fathers were coordinated separately from each other. Mothers' perceived helpfulness served as a driver of returning adolescents back to homeostasis. Conclusions: The results illustrate a dynamic process whereby numerous facets of self- and social-regulation are coordinated in order to return diabetes management to a stable state.

Attention Problems as a Predictor of Type 1 Diabetes Adherence and Metabolic Control Across Adolescence.

Objective: Management of type 1 diabetes is a difficult self-regulatory process requiring continued attention to complex regimen tasks. The purpose of this study was to examine whether youths' attention problems were associated with poorer adherence and HbA1c across time, and whether higher parental involvement reduced these associations. Methods: Adolescents with type 1 diabetes (N = 199, M age = 12.43 years, SD = 1.50) and their mothers rated youths' attention problems and adherence at three time points. Adolescents rated parents' diabetes-specific monitoring and behavioral involvement. HbA1c was collected from medical records. Results: Adolescents' (but not mothers') greater reports of attention problems compared with their average related to lower adherence across time. Adolescents' (but not mothers') reports of greater attention problems compared with their average related to lower adherence across time. Conclusions: Youth attention problems may help us understand poor adherence, and interventions to promote parental involvement may buffer this risk.

Adolescent Disclosure to Parents and Daily Management of Type 1 Diabetes.

Objective: To examine how adolescents' daily disclosure to parents about type 1 diabetes management may foster a process whereby parents gain knowledge and are viewed as helpful in ways that may aid diabetes management. Methods: A total of 236 late adolescents (M age = 17.76) completed a 14-day diary where they reported daily disclosure to, and solicitation from, their parents, how knowledgeable and helpful parents were, and their self-regulation failures and adherence; blood glucose was gathered from meters. Results: Multilevel models revealed that adolescent disclosure occurred in the context of greater parent solicitation and face-to-face contact and was positively associated with adolescents' perceptions of parental knowledge and helpfulness. Disclosure to mothers (but not to fathers) was associated with better diabetes management (fewer self-regulation failures, better adherence). Conclusions: Adolescent disclosure may be an important way that parents remain knowledgeable about diabetes management and provide assistance that serves to support diabetes management.

A multivariate dynamic systems model for psychotherapy with more than one client.

The dynamics of the give and take between therapist and client(s) is frequently of interest to therapy process researchers. Characterizing the ways that therapists respond to clients and clients respond to therapists can be challenging in therapeutic encounters involving a single therapist and a single client. The complexity of this challenge increases as the number of people involved in a therapeutic encounter increases not only because there are more people responding to one another but also because the patterns of responding can become more complex. This manuscript demonstrates how dyadic cross-lagged panel models can be extended to psychotherapeutic encounters involving 3 people and used to test processes that exist between dyadic subsets of the larger group as well as the group as one cohesive unit. Three hundred seventy-nine talk turns of fundamental frequency from a couple therapy session were modeled using 3 dyadic cross-lagged panel models, and each individual's respiratory sinus arrhythmia (RSA) was treated as a moderator. Although the regression coefficients for each dyadic subset (e.g., therapist-husband) were nonsignificant, an eigenvalue/eigenvector decomposition of the regression coefficients from the 3 dyadic cross-lagged panel models suggests that interdependence exists at the level of the whole group (i.e., therapist-husband-wife) rather than between pairs of individuals within the group (e.g., husband-wife). Further, an interaction involving husband's RSA suggested that interdependence involving the husband ceased when the husband displayed greater regulatory effort. This combination of statistical methods allows for clearly distinguishing between dyadic therapeutic processes and group-level therapeutic processes. (PsycINFO Database Record

Modeling Change in Project Duration and Completion: Scheduling Dynamics of NASA's Exploration Flight Test 1 (EFT-1) Activities.

In complex work domains and organizations, understanding schedule-ing dynamics can ensure objectives are reached and delays are mitigated. In the current paper, we examine the scheduling dynamics for NASA's Exploration Flight Test 1 (EFT-1) activities. For this examination, we specifically modeled simultaneous change in percent complete and estimated duration for a given project as they were included in monthly reports over time. In short, we utilized latent change score mixture modeling to extract the attractor dynamics within the scheduling data. We found three primarily patterns: an attractor at low duration, low percent complete; a saddle that was attractive toward full completion and repelled duration away from five months, and an attractor at full completion and high duration. We replicated these three patterns using multilevel modeling. Then, we examined how task dependencies, in terms of the number of predecessors and successors, affected the probability of exhibiting a given pattern over time. Thus, we offer a flexible method for understanding the patterns that can characterize scheduling dynamics as well as other dynamical systems. Several recommendations for future directions are discussed.

Transactional relations between caregiving stress, executive functioning, and problem behavior from early childhood to early adolescence.

Developmental psychopathologists face the difficult task of identifying the environmental conditions that may contribute to early childhood behavior problems. Highly stressed caregivers can exacerbate behavior problems, while children with behavior problems may make parenting more difficult and increase caregiver stress. Unknown is: (a) how these transactions originate, (b) whether they persist over time to contribute to the development of problem behavior and (c) what role resilience factors, such as child executive functioning, may play in mitigating the development of problem behavior. In the present study, transactional relations between caregiving stress, executive functioning, and behavior problems were examined in a sample of 1,388 children with prenatal drug exposures at three developmental time points: early childhood (birth to age 5), middle childhood (ages 6 to 9), and early adolescence (ages 10 to 13). Transactional relations differed between caregiving stress and internalizing versus externalizing behavior. Targeting executive functioning in evidence-based interventions for children with prenatal substance exposure who present with internalizing problems and treating caregiving psychopathology, depression, and parenting stress in early childhood may be particularly important for children presenting with internalizing behavior.

Latent profiles of executive functioning in healthy young adults: evidence of individual differences in hemispheric asymmetry.

Two competing theoretical models of individual differences in executive functioning (EF) were examined: the Prefrontal Convexity Model and the Hemispheric Asymmetry Model. Neurologically healthy individuals (N = 315; mean age 20.8) completed a modified switching task (MST) and the Attention Network Test (ANT) in a single testing session. Data analysis was conducted in two phases. In the first phase (model identification), latent profile analysis was applied to MST variables measuring the abilities to form, switch, and maintain mental sets under conditions designed to tax left or right hemisphere resources. In the second phase (model validation), participant clusters obtained from the first phase were compared on the ANT. The Model Identification phase yielded a 3-profile solution consistent with the Hemispheric Asymmetry Model. Profile 1 (N = 203) was characterized by average EF performances. Profile 2 (N = 43) revealed a set maintenance weakness under non-verbal conditions. Profile 3 (N = 38) demonstrated weaknesses in cognitive flexibility combined with poor executive performances under verbal conditions. The Model Validation phase confirmed group differences. Profile 1 demonstrated average EF performances. Profile 2 demonstrated distractibility and decreased alertness, consistent with a right hemisphere weakness. Profile 3 demonstrated cognitive rigidity in the absence of external cues, consistent with a left hemisphere weakness. Individual differences in EF appear to follow a Hemispheric Asymmetry Model of EF among neurologically healthy adults. Investigating the relationship between hemispherically mediated executive functions and other individual difference factors known to confer health risk or resilience could inform numerous disciplines within the field of psychology.

Adolescents', mothers', and fathers' reports of adherence across adolescence and their relation to HbA1c and daily blood glucose.

This study examined what is measured by adolescents', mothers', and fathers' reports of adolescents' adherence to the type 1 diabetes regimen and how such reports relate to HbA1c and daily blood glucose. Two-hundred fifty-two adolescents (M age = 12.49 at baseline), mothers, and 188 fathers completed an adapted Self-Care Inventory (LaGreca et al. in Child Health Care 19(3):132-139, 1990) every 6 months for 2.5 years, HbA1c was gathered from medical records, and daily number of blood glucose tests (BGT) and blood glucose mean (BGM) were obtained from glucose meters at one time point. A multitrait-multimethod approach decomposing adherence indicated that fathers' reports reflected a stable perception across time, mothers' reports a shared view within the family that varied with HbA1c across time, and adolescents' reports a unique view. Fathers' and mothers' reports were related to HbA1c; adolescents' reports were not, but were uniquely associated with BGT. Family members' adherence reports capture different information across time, with implications for measuring adherence and for family processes.

Secrecy From Parents and Type 1 Diabetes Management in Late Adolescence.

OBJECTIVES: This study examined (a) associations of parent-adolescent relationship characteristics and adolescent problem behavior with late adolescents' secrecy from parents about type 1 diabetes management, and (b) whether secrecy was associated with diabetes and psychological outcomes independently of these factors. METHODS: Adolescents (N = 247, Mage = 17.76 years) completed survey measures of diabetes-related secrecy from parents, disclosure, parental acceptance, parental knowledge, and conduct problems. Mothers and adolescents reported on adolescent adherence to diabetes regimens and adolescents reported their depressive symptoms. Glycemic control was obtained from HbA1c test kits. RESULTS: Adolescent-reported disclosure to parents was uniquely negatively associated with secrecy from parents. Controlling for relationship variables, conduct problems, and sociodemographic and illness-related variables, secrecy from mothers was uniquely associated with poorer glycemic control and secrecy from both parents was associated with lower adherence. CONCLUSIONS: Secrecy about type 1 diabetes management is uniquely associated with diabetes outcomes independent of other relationship characteristics and problem behaviors.