Peripheral Neuropathy in Older People Is Associated with Reduced Life Expectancy.

INTRODUCTION: We analyzed data from a prospective cohort of older primary care patients to determine whether the presence of peripheral neuropathy (PN) was associated with premature mortality and to investigate potential mechanisms. METHODS: PN was defined as the presence of 1 or more bilateral lower extremity sensory deficits detectable by physical examination. Mortality was determined from key contacts and Internet sources. Statistical models were used to evaluate the association between PN and mortality. RESULTS: Bilateral lower extremity neurological deficits were common, reaching 54% in those 85 and older. PN was strongly associated with earlier mortality. Mean survival time for those with PN was 10.8 years, compared with 13.9 years for subjects without PN. PN was also indirectly associated through impaired balance. CONCLUSIONS: In this relatively healthy cohort of older primary care patients, PN detectable by physical examination was extremely common and strongly associated with earlier mortality. One possible mechanism involves loss of balance, though our data were insufficient to determine whether poor balance led to injurious falls or to less-specific declines in health. These findings may warrant further studies to determine the causes of age-associated PN and potential impact of early detection and balance improvement and other fall prevention strategies.

The need for a measurement-based care professional practice guideline.

Professional practice guidelines (PPGs) are intended to promote a high level of professional practice and serve as an educational resource, providing pragmatic guidance in a clinical area for psychologists. Measurement-based care (MBC) is an evidence-based psychological practice with accumulating empirical support and alignment with patient-centered care. In connection with the American Psychological Association's Advisory Committee for Measurement-based Care and the Mental and Behavioral Health Registry, this article outlines various lines of support for the development and implementation of an MBC PPG. In addition to research evidence, we address the demonstrated need of this guideline across three domains: public benefit, professional guidance, and legal and regulatory issues. Consistent with the aspirational spirit of a PPG, this article proposes a draft PPG statement and highlights how an MBC PPG would improve service delivery, facilitate implementation of an evidence-based practice associated with symptom reduction, improved retention, and greater patient satisfaction, as well as create a framework that will better align changes in reimbursement models with patients' and providers' treatment goals. We also identify key future directions and critical gaps in MBC science and implementation that require attention. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Whole-genome sequencing-based phylogeny, antibiotic resistance, and invasive phenotype of Escherichia coli strains colonizing the cervix of women in preterm labor.

BACKGROUND: Escherichia coli is a major neonatal pathogen and the leading cause of early-onset sepsis in preterm newborns. Maternal E. coli strains are transmitted to the newborn causing invasive neonatal disease. However, there is a lack of data regarding the phenotypic and genotypic characterization of E. coli strains colonizing pregnant women during labor. METHODS: This prospective study performed at the University of Oklahoma Medical Center (OUHSC) from March 2014 to December 2015, aimed to investigate the colonization rate, and the phylogeny, antibiotic resistance traits, and invasive properties of E. coli strains colonizing the cervix of fifty pregnant women diagnosed with preterm labor (PTL). Molecular analyses including bacterial whole-genome sequencing (WGS), were performed to examine phylogenetic relationships among the colonizing strains and compare them with WGS data of representative invasive neonatal E. coli isolates. Phenotypic and genotypic antibiotic resistance traits were investigated. The bacteria's ability to invade epithelial cells in vitro was determined. RESULTS: We recruited fifty women in PTL. Cervical samples yielded E. coli in 12 % (n=6). The mean gestational age was 32.5 (SD±3.19) weeks. None delivered an infant with E. coli disease. Phenotypic and genotypic antibiotic resistance testing did not overall demonstrate extensive drug resistance traits among the cervical E. coli isolates, however, one isolate was multi-drug resistant. The isolates belonged to five different phylogroups, and WGS analyses assigned each to individual multi-locus sequence types. Single nucleotide polymorphism-based comparisons of cervical E. coli strains with six representative neonatal E. coli bacteremia isolates demonstrated that only half of the cervical E. coli isolates were phylogenetically related to these neonatal invasive strains. Moreover, WGS comparisons showed that each cervical E. coli isolate had distinct genomic regions that were not shared with neonatal E. coli isolates. Cervical and neonatal E. coli isolates that were most closely related at the phylogenetic level had similar invasion capacity into intestinal epithelial cells. In contrast, phylogenetically dissimilar cervical E. coli strains were the least invasive among all isolates. CONCLUSIONS: This pilot study showed that a minority of women in PTL were colonized in the cervix with E. coli, and colonizing strains were not phylogenetically uniformly representative of E. coli strains that commonly cause invasive disease in newborns. Larger studies are needed to determine the molecular characteristics of E. coli strains colonizing pregnant women associated with an increased risk of neonatal septicemia.

Maternal diabetes alters microRNA expression in fetal exosomes, human umbilical vein endothelial cells and placenta.

BACKGROUND: Exposure to diabetes in utero influences future metabolic health of the offspring. MicroRNAs (miRNA) are small noncoding RNAs that may contribute mechanistically to the effects on offspring imparted by diabetes mellitus (DM) during pregnancy. We hypothesized that exposure to DM during pregnancy influences select miRNAs in fetal circulation, in human umbilical vein endothelial cells (HUVEC), and placenta. METHODS: miRNA abundance was quantified using real-time PCR from RNA isolated from umbilical cord serum exosomes, HUVEC, and placenta exposed to diabetes or normoglycemia during pregnancy. The abundance of each of these miRNAs was determined by comparison to a known standard and the relative expression assessed using the 2-ΔΔCt method. Multivariable regression models examined the associations between exposure to diabetes during pregnancy and miRNA expression. RESULTS: miR-126-3p was highly abundant in fetal circulation, HUVEC, and placenta. Diabetes exposure during pregnancy resulted in lower expression of miR-148a-3p and miR-29a-3p in the HUVEC. In the placenta, for miR-126-3p, there was a differential effect of DM by birth weight between DM versus control group, expression being lower at the lower birth weight, however not different at the higher birth weight. CONCLUSION: Exposure to DM during pregnancy alters miRNA expression in the offspring in a tissue-specific manner. IMPACT: miRNAs are differentially expressed in fetal tissues from offspring exposed to in utero diabetes mellitus compared to those who were not exposed. miRNA expression differs among tissue types (human umbilical vein endothelial cells, placenta and circulation exosomes) and response to diabetes exposure varies according to tissue of origin. miRNA expression is also affected by maternal and infant characteristics such as infant birth weight, infant sex, maternal age, and maternal BMI. miRNAs might be one of the potential mechanisms by which offspring's future metabolic status may be influenced by maternal diabetes mellitus.

Generalizing findings from a randomized controlled trial to a real-world study of the iLookOut, an online education program to improve early childhood care and education providers' knowledge and attitudes about reporting child maltreatment.

In recent years, real-world studies (RWS) are gaining increasing interests, because they can generate more realistic and generalizable results than randomized controlled clinical trials (RCT). In 2017, we published a RCT in 741 early childhood care and education providers (CCPs). It is the Phase I of our iLookOut for Child Abuse project (iLookOut), an online, interactive learning module about reporting suspected child maltreatment. That study demonstrated that in a RCT setting, the iLookOut is efficient at improving CCPs' knowledge of and attitudes towards child maltreatment reporting. However, the generalizability of that RCT's results in a RWS setting remains unknown. To address this question, we design and conduct this large RWS in 11,065 CCPs, which is the Phase II of the iLookOut. We hypothesize replication of the earlier RCT findings, i.e., the iLookOut can improve CCPs' knowledge of and attitudes toward child maltreatment reporting in a real world setting. In addition, this RWS also explores whether demographic factors affect CCPs' performance. Results of this RWS confirmed the generalizability of the previous RCT's results in a real world setting. It yielded similar effect sizes for knowledge and attitudes as were found in the earlier RCT. Cohen's d for knowledge improvement was 0.95 in that RCT, 0.96 in this RWS; Cohen's d for attitude improvement was 0.98 in that RCT, 0.80 in this RWS. Also, we found several significant differences in knowledge and attitude improvement with regard to age, race, education, and employment status. In conclusion, iLookOut improves knowledge and attitudes of CCPs about child maltreatment prevention and reporting in a real-world setting. The generalizability of the initial RCT findings to this RWS provides strong evidence that the iLookout will be effective in other real world settings. It can be a useful model for other interventions aimed at preventing child maltreatment. Clinical trial registration for the original RCT: NCT02225301 (ClinicalTrials.gov Identifier).

Responding to a 100-Year-Old Challenge from Fisher: A Biometrical Analysis of Adult Height in the NLSY Data Using Only Cousin Pairs.

In 1918, Fisher suggested that his research team had consistently found inflated cousin correlations. He also commented that because a cousin sample with minimal selection bias was not available the cause of the inflation could not be addressed, leaving this inflation as a challenge still to be solved. In the National Longitudinal Survey of Youth (the NLSY79, the NLSY97, and the NLSY-Children/Young Adult datasets), there are thousands of available cousin pairs. Those in the NLSYC/YA are obtained approximately without selection. In this paper, we address Fisher's challenge using these data. Further, we also evaluate the possibility of fitting ACE models using only cousin pairs, including full cousins, half-cousins, and quarter-cousins. To have any chance at success in such a restricted kinship domain requires an available and highly-reliable phenotype; we use adult height in our analysis. Results provide a possible answer to Fisher's challenge, and demonstrate the potential for using cousin pairs in a stand-alone analysis (as well as in combination with other biometrical designs).

Positive Parenting Matters in the Face of Early Adversity.

INTRODUCTION: A negative relationship between adverse childhood experiences and both physical and mental health in adulthood is well established, as is the positive impact of parenting on child development and future health. However, few studies have investigated unique influences of adverse childhood experiences and positive parenting together within a large, diverse early childhood sample. METHODS: The study used data on all children aged 0-5 years (n=29,997) from the National Survey of Children's Health 2011/2012 to examine effects of positive parenting practices and adverse childhood experiences on early childhood social-emotional skills and general development. All analyses were performed in 2017 and 2018. RESULTS: More than a third of the sample reported experiencing at least one adverse childhood experience. More than a fourth (26.7%) met study criteria for social-emotional deficits, and 26.2% met criteria for developmental delay risks. The number of adverse childhood experiences exhibited negative marginal associations with social-emotional deficits and developmental delay risks, whereas the number of positive parenting practices showed independent protective effects. Risks associated with an absence of positive parenting were often greater than those of four or more adverse childhood experiences, even among no/low adversity families. The population attributable fractions for social-emotional deficits and developmental delay risks were 17.3% and 13.9% (translating to prevalence reductions of 4.5% and 3.6%) when adopting all positive parenting practices and 4.5% and 7.2% (prevalence reductions of 1.2% and 1.9%) when eliminating adverse childhood experiences. CONCLUSIONS: The number of adverse childhood experiences was associated with both social-emotional deficits and developmental delay risks in early childhood; however, positive parenting practices demonstrated robust protective effects independent of the number of adverse childhood experiences. This evidence further supports promotion of positive parenting practices at home, especially for children exposed to high levels of adversity.

The Association Between Race/Ethnicity and Socioeconomic Factors and the Diagnosis and Treatment of Children with Attention-Deficit Hyperactivity Disorder.

OBJECTIVE: Assessing race/ethnicity and socioeconomic status (SES) relationships with Attention-Deficit/Hyperactivity Disorder (ADHD) diagnosis, treatment, and access to care has yielded inconsistent results often based only on parent-report. In contrast, this study used broader ADHD diagnostic determination including case-definition to examine these relationships in a multisite elementary-school-based sample. METHOD: Secondary analysis of children with and without ADHD per parent and teacher-reported Diagnostic and Statistical Manual of Mental Disorders (DSM) criteria evaluated SES, race/ethnicity, and other variables through simple bivariate/multivariable models within and across: parent-reported diagnosis, medication treatment, and meeting ADHD study case-definition. RESULTS: The total sample included 51.9% male, 51.3% White, and 53.1% with private insurance; 10% had parent-reported ADHD diagnoses while 8.3% met ADHD study case-definition. In multivariable models, White children had higher odds of parent-reported diagnoses than Black, Hispanic, and Other Race/Ethnicity children (p < 0.05), but only Hispanic children had lower odds of being case-positive (<0.05); males and children in single-parent households had higher odds of parent-reported diagnoses and being case-positive (p < 0.05); and children who were White, male, and had health insurance had higher odds of taking medication (p < 0.05). Among children who were case-positive, those with Medicaid, White, and 2-parent statuses had higher odds of parent-reported diagnoses (p < 0.05). CONCLUSION: Children with underlying ADHD appear more likely to have assessment/medication treatment access if they are White, male, have health insurance (particularly Medicaid), and live in 2-parent households. While boys and children raised by single parents may have higher rates of ADHD diagnoses, false-positive diagnostic risk also appeared higher, inviting further investigation.

Heterotaxy syndrome and associated arrhythmias in pediatric patients.

BACKGROUND: Heterotaxy syndrome (HS) is a rare disorder with complex anatomy involving misarrangements of the cardiac conduction system. Arrhythmias may be related to anatomic variations and contribute to morbidity. OBJECTIVE: The purpose of this study was to investigate the associations between arrhythmias, anatomy, and outcomes in a large HS cohort. METHODS: A single-center retrospective review of patients ≤21 years of age diagnosed with HS was performed. RESULTS: A total of 337 patients were included in the study. During median follow-up of 7 years (interquartile range 2-16 years), 129 patients (38%) had ≥1 clinically significant rhythm disturbance: tachyarrhythmias in 75 (22%), bradyarrhythmias in 29 (9%), and both in 25 (7%). Factors associated with tachyarrhythmia by multivariate analysis were at least moderate atrioventricular valve regurgitation (hazard ratio [HR] 1.66; 95% confidence interval [CI] 1.11-2.50), single ventricle anatomy (HR 2.30; 95% CI 1.09-4.85), and pulmonary venous obstruction (HR 2.33; 95% CI 1.45-3.76). Isomerism subtype was not associated with tachyarrhythmias. In adjusted and unadjusted analyses, bradyarrhythmias (symptomatic sinus/atrial bradycardia and high-grade or complete heart block) were associated with left atrial isomerism (LAI) compared to right atrial isomerism (HR 7.12; 95% CI 3.01-16.9). The overall transplant-free survival of the cohort was 66%. Tachyarrhythmias, but not bradyarrhythmias, were associated with mortality or need for transplant (HR 2.24; 95% CI 1.45-3.46). CONCLUSION: Clinically significant arrhythmias are common in HS. Although bradyarrhythmias are associated with LAI, tachyarrhythmia occurrence may depend more on hemodynamic and anatomic factors than isomerism subtype. Tachyarrhythmias, but not bradyarrhythmias, are associated with death or need for transplant.

The NLSY Kinship Links: Using the NLSY79 and NLSY-Children Data to Conduct Genetically-Informed and Family-Oriented Research.

The National Longitudinal Survey of Youth datasets (NLSY79; NLSY-Children/Young Adults; NLSY97) have extensive family pedigree information contained within them. These data sources are based on probability sampling, a longitudinal design, and a cross-generational and within-family data structure, with hundreds of phenotypes relevant to behavior genetic (BG) researchers, as well as to other developmental and family researchers. These datasets provide a unique and powerful source of information for BG researchers. But much of the information required for biometrical modeling has been hidden, and has required substantial programming effort to uncover-until recently. Our research team has spent over 20 years developing kinship links to genetically inform biometrical modeling. In the most recent release of kinship links from two of the NLSY datasets, the direct kinship indicators included in the 2006 surveys allowed successful and unambiguous linking of over 94 % of the potential pairs. In this paper, we provide details for research teams interested in using the NLSY data portfolio to conduct BG (and other family-oriented) research.

The psychometric properties of the Vanderbilt attention-deficit hyperactivity disorder diagnostic parent rating scale in a community population.

OBJECTIVE: To examine the psychometric properties of the Vanderbilt ADHD Diagnostic Parent Rating Scale (VADPRS) using a community-based sample of primarily elementary and middle school-aged children. METHOD: Participants were initially recruited from 41 elementary schools in 5 Oklahoma school districts including urban, suburban, and rural students. Vanderbilt rating scales were obtained from all teachers (n = 601) and sampled parents (n = 587) of the participating children. Construct validity was assessed by confirmatory factor analysis of the 45 items that made up the 4 scales of inattention, hyperactivity, conduct/oppositional problems, and anxiety/depression problems. Reliability was evaluated from internal consistency, test-retest, and interrater agreement perspectives. Criterion validity was evaluated via comparisons to a structured psychiatric interview with the parents using the Diagnostic Interview Schedule for Children-IV. RESULTS: A 4-factor model (inattention, hyperactivity, conduct/oppositional problems, and anxiety/depression problems) fit the data well once discarding conduct items that were infrequently endorsed. The estimates of coefficient alpha ranged from .91 to .94 and the analogous KR20 coefficient for a binary item version of the scale ranged from .88 to .91. Test-retest reliability exceeded .80 for all summed scale scores. The VADPRS produced a sensitivity of .80, specificity of .75, positive predictive value of .19, and negative predictive value of .98 when predicting an attention-deficit hyperactivity disorder (ADHD) case definition that combined teacher's Vanderbilt ADHD Diagnostic Teacher Rating Scale and parent diagnostic interview responses. CONCLUSION: The confirmation of the construct and concurrent criterion validities found in this study further support the utility of the VADPRS as a diagnostic rating scale for ADHD.

The psychometric properties of the Vanderbilt attention-deficit hyperactivity disorder diagnostic teacher rating scale in a community population.

OBJECTIVE: This study examined the psychometric properties of the Vanderbilt AD/HD Diagnostic Teacher Rating Scale (VADTRS). METHODS: Information was collected from teachers and parents in 5 school districts (urban, suburban, and rural). All teachers in participating schools were asked to complete the VADTRS on all their students. Construct validity was evaluated through an exploratory factor analysis investigation of the 35 items that made up the 4 scales of inattention, hyperactivity, conduct/oppositional problems, and anxiety/depression problems. Convergent validity was assessed among a subsample of participants whose teachers completed the Strengths and Difficulties Questionnaire (SDQ). Finally, predictive validity was examined for another subsample of high- and low-risk children whose parents completed a structured psychiatric interview, the Diagnostic Interview Schedule for Children-IV. RESULTS: For construct validity, a 4-factor model (inattention, hyperactivity, conduct/oppositional, and anxiety/depression problems) fits the data well. The estimates of the KR20 coefficient for a binary item version of the scale ranged from .85 to .94. Convergent validity with the SDQ was high (Pearson's correlations > .72) for these 4 factors. For predictive validity, the VADTRS produced a sensitivity of .69, specificity of .84, positive predictive value of .32, and negative predictive value of .96 when predicting future case definitions among children whose parents completed a diagnostic interview. CONCLUSION: The confirmation of the construct and convergent validity and acceptable scale reliabilities found in this study further supports the utility of the VADTRS as a diagnostic rating scale for attention-deficit hyperactivity disorder. The low predictive validity further demonstrates the need for multiple observers in establishing the diagnosis.

Biodemographic modeling of the links between fertility motivation and fertility outcomes in the NLSY79.

In spite of long-held beliefs that traits related to reproductive success tend to become fixed by evolution with little or no genetic variation, there is now considerable evidence that the natural variation of fertility within populations is genetically influenced and that a portion of that influence is related to the motivational precursors to fertility. We conduct a two-stage analysis to examine these inferences in a time-ordered multivariate context. First, using data from the National Longitudinal Survey of Youth, 1979, and LISREL analysis, we develop a structural equation model in which five hypothesized motivational precursors to fertility, measured in 1979-1982, predict both a child-timing and a child-number outcome, measured in 2002. Second, having chosen two time-ordered sequences of six variables from the SEM to represent our phenotypic models, we use Mx to conduct both univariate and multivariate behavioral genetic analyses with the selected variables. Our results indicate that one or more genes acting within a gene network have additive effects that operate through child-number desires to affect both the timing of the next child born and the final number of children born, that one or more genes acting through a separate network may have additive effects operating through gender role attitudes to produce downstream effects on the two fertility outcomes, and that no genetic variance is associated with either child-timing intentions or educational intentions.

Pediatricians' attitudes and practices on ADHD before and after the development of ADHD pediatric practice guidelines.

PURPOSE: The study aims to assess the changes in attitudes and practices about ADHD reported by AAP fellows between 1999 and 2005 during which AAP ADHD guidelines, training, and quality improvement initiatives occurred. METHOD: The study assesses AAP-initiated surveys that were conducted between 1999 and 2005 and involving a random sample of 1,000 and 1,603 pediatricians, respectively. RESULTS: The findings reveal that significant, although modest, increases occurred in pediatric practitioners' self-reported adherence to the guidelines. About 81% of respondents reported routine use of formal diagnostic criteria (up from 67%), and 67% of the respondents routinely use ADHD teacher rating scales (compared to 49% in the 1999 survey). Findings further reveal that treatment with stimulant medications was used extensively by pediatricians from both surveys; more pediatricians in the 2005 survey reported use of a second stimulant if the first did not work, and still more reported almost always providing parent training, although the estimated number remained only about a quarter of the total; and greater familiarity with the initiatives predicted better reported adherence to the guidelines. CONCLUSION: The reported behaviors of practitioners have moved in the direction of greater adherence with the recommended AAP ADHD guidelines, and there was a positive response to, and a greater use of, the materials developed to enhance practice. The authors infer that practice changes may be due to many factors, including AAP guidelines and associated implementation efforts. Changing physician practices needs to be sustained through a continuing process that requires multiple, varying, sustained efforts directed at physicians, other providers, and families.

The cross-generational mother-daughter-aunt-niece design: establishing validity of the MDAN design with NLSY fertility variables.

Using National Longitudinal Survey of Youth (NLSY) fertility variables, we introduce and illustrate a new genetically-informative design. First, we develop a kinship linking algorithm, using the NLSY79 and the NLSY-Children data to link mothers to daughters and aunts to nieces. Then we construct mother-daughter correlations to compare to aunt-niece correlations, an MDAN design, within the context of the quantitative genetic model. The results of our empirical illustration, which uses DF Analysis and generalized estimation equations (GEE) to estimate biometrical parameters from NLSY79 sister-sister pairs and their children in the NLSY-Children dataset, provide both face validity and concurrent validity in support of the efficacy of the design. We describe extensions of the MDAN design. Compared to the typical within-generational design used in most behavior genetic research, the cross-generational feature of this design has certain advantages and interesting features. In particular, we note that the equal environment assumption of the traditional biometrical model shifts in the context of a cross-generational design. These shifts raise questions and provide motivation for future research using the MDAN and other cross-generational designs.

Meta-analysis of treatment for child sexual behavior problems: practice elements and outcomes.

This meta-analysis of 11 treatment outcome studies evaluated 18 specific treatments of sexual behavior problems (SBP) as a primary or secondary target. Specifically, it examines relations among child characteristics, treatment characteristics (including practice elements), and short-term outcome (including sexual and general behavior problems). Utilizing pre- and postintervention results, the overall degree of change over the course of treatment was estimated at a 0.46 and 0.49 standard deviation decline in SBP and general behavior problems, respectively. As hypothesized, the caregiver practice element Parenting/Behavior Management Skills (BPT) predicted the Child Sexual Behavior Inventory (and the Child Behavior Checklist when BPT was combined with caregiver Rules about Sexual Behaviors). In contrast, practice elements that evolved from Adult Sex Offender (ASO) treatments were not significant predictors. BPT and preschool age group provided the best model fit and more strongly predicted outcome than broad treatment type classifications (e.g., Play Therapy or Cognitive Behavior Therapy). Results question current treatments for children with SBP that are based on ASO models of treatment without caregiver involvement.

Abstract: A Multi-Level Model of Individual Differences in Speed/Accuracy Tradeoff (SATin).

Individuals performing an experimental cognitive task have a choice whether to favor accuracy, speed, or weight them both equally. Models of speed/ accuracy tradeoff have been proposed in the assessment literature ( van der Linden, 2007 ) and experimental literature ( Ratcliff & Rouder, 1998 ). However, these models do not estimate individual differences in choice of speed/ accuracy tradeoff at between- and within-subjects levels. The top of Figure 1 presents the equations and path diagram for the SATin model. Individual differences in speed/ accuracy tradeoff will be modeled at two levels with, 1) variability in Tradeoff (between-subject level, Level 2) and 2) variability in c (within-subject level, Level 1). An individual's Tradeoff factor score represents the individual's distributional position relative to others regarding whether they favor speed (values < 0), accuracy (values > 0), or neither (value = 0). A negative c indicates that the individual is trading off speed and accuracy for these particular trials, whereas a positive and zero c indicate the individual is not trading off. [Figure: see text] Panels 1 and 2 illustrate Simpson's paradox, where speed/ accuracy tradeoff occurs in opposing directions at between- and within-subject levels. This highlights the need for a multi-level model as the researcher would draw opposing conclusions by observing only one of these levels. Simulations studies compared the SATin model to a popular model in cognitive psychology that uses speed alone to estimate ability. SATin outperformed this model by accounting for substantially more variance in actual ability.

Multivariate Cholesky models of human female fertility patterns in the NLSY.

Substantial evidence now exists that variables measuring or correlated with human fertility outcomes have a heritable component. In this study, we define a series of age-sequenced fertility variables, and fit multivariate models to account for underlying shared genetic and environmental sources of variance. We make predictions based on a theory developed by Udry [(1996) Biosocial models of low-fertility societies. In: Casterline, JB, Lee RD, Foote KA (eds) Fertility in the United States: new patterns, new theories. The Population Council, New York] suggesting that biological/genetic motivations can be more easily realized and measured in settings in which fertility choices are available. Udry's theory, along with principles from molecular genetics and certain tenets of life history theory, allow us to make specific predictions about biometrical patterns across age. Consistent with predictions, our results suggest that there are different sources of genetic influence on fertility variance at early compared to later ages, but that there is only one source of shared environmental influence that occurs at early ages. These patterns are suggestive of the types of gene-gene and gene-environment interactions for which we must account to better understand individual differences in fertility outcomes.