Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 22
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
Early Educ Dev ; 33(1): 1-16, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35082478

RESUMEN

Studies with extensive observations of real-life emotions at school are rare but might be especially useful for predicting school-related outcomes. This study evaluated observations of negative emotion expressivity in lunch and recreation settings across kindergarten, first grade, and second grade (N = 301), kindergarten teachers' reports of children's effortful control, and kindergarten and second grade teachers' reports of their perceived conflict with children. In latent growth curve analyses, we tested whether individual trajectories of negative expressivity from kindergarten to second grade, based on estimated slopes, predicted teacher-student conflict in second grade, and whether effortful control in kindergarten moderated this association. RESEARCH FINDINGS: Negative expressivity levels in kindergarten significantly predicted higher levels of teacher-student conflict in second grade, controlling prior teacher-student conflict. Furthermore, greater increases in negative expressivity from kindergarten to second grade were associated with higher teacher-student conflict in second grade especially for children who had difficulties with effortful control in kindergarten. PRACTICE OR POLICY: Results from this study have the potential to inform programs focused on reducing teacher-student conflict. The findings highlight the possibility of targeting both effortful control and negative emotion in the early elementary school transition as a means to improve teacher-student relationships.

2.
J Educ Psychol ; 111(3): 542-555, 2019 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-31186581

RESUMEN

The goal of the study was to examine whether target children's temperamental negative emotional expressivity (NEE) and effortful control in the fall of kindergarten predicted academic adjustment in the spring and whether a classmate's NEE and effortful control moderated these relations. Target children's NEE and effortful control were measured in the fall via multiple methods, academic adjustment was measured via reading and math standardized tests in the spring, and observations of engagement in the classroom were conducted throughout the year. In the fall, teachers nominated a peer with whom each target child spent the most time and rated that peer's temperament. Target children with high effortful control had high reading and math achievement (ps = .04 and < .001, respectively), and children with low NEE increased in engagement during the year (p < .001). Peers' temperament did not have a direct relation to target children's academic adjustment. Peers' negative emotion, however, moderated the relation between target children's effortful control, as well as NEE, and changes in engagement (ps = .03 and .05, respectively). Further, peers' effortful control moderated the relations between target children's NEE and reading and changes in engagement (ps = .02 and .04, respectively). In each case, target children's temperament predicted the outcome in expected directions more strongly when peers had low NEE or high effortful control. Results are discussed in terms of how children's temperamental qualities relate to academic adjustment, and how the relation between NEE and changes in engagement, in particular, depends on peers' temperament.

3.
J Exp Child Psychol ; 176: 101-112, 2018 12.
Artículo en Inglés | MEDLINE | ID: mdl-30149242

RESUMEN

The associations between children's (N = 301) observed expression of positive and negative emotion in school and symptoms of psychological maladjustment (i.e., depressive and externalizing symptoms) were examined from kindergarten to first grade. Positive and negative emotional expressivity levels were observed in school settings, and teachers reported on measures of children's externalizing and depressive symptoms. In longitudinal panel models testing bidirectional paths, depressive symptoms in kindergarten were negatively associated with positive expressivity in first grade but not vice versa. Children's externalizing symptoms in kindergarten predicted higher negative expressivity in school in first grade. There was also significant prediction of externalizing in first grade by negative expressivity during kindergarten. Implications about child psychological maladjustment in early schooling are discussed.


Asunto(s)
Depresión/psicología , Emociones , Control Interno-Externo , Estudiantes/psicología , Preescolar , Femenino , Humanos , Masculino , Instituciones Académicas
4.
J Educ Psychol ; 110(3): 324-337, 2018 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-29861505

RESUMEN

We examined individual trajectories, across four time points, of children's (N = 301) expression of negative emotion in classroom settings and whether these trajectories predicted their observed school engagement, teacher-reported academic skills, and passage comprehension assessed with a standardized measure in first grade. In latent growth curve analyses, negative expressivity declined from kindergarten to first grade with significant individual differences in trajectories. Negative expressivity in kindergarten inversely predicted first grade school engagement and teacher-reported academic skills, and the slope of negative expressivity from kindergarten to first grade inversely predicted school engagement (e.g., increasing negative expressivity was associated with lower school engagement). In addition, we examined if prior academic functioning in kindergarten moderated the association between negative expressivity (level in kindergarten and change over time) and academic functioning in first grade. The slope of negative expressivity was negatively associated with first grade school engagement and passage comprehension for children who had lower kindergarten school engagement and passage comprehension, respectively, but was unrelated for those with higher academic functioning in kindergarten. That is, for children who had lower kindergarten school engagement and passage comprehension, greater declines in negative expressivity were associated with higher first grade school engagement and passage comprehension, respectively. The findings suggest that negative emotional expressivity in school is associated with academic outcomes in first grade and, in some cases, this association is more pronounced for children who had lower kindergarten academic functioning.

5.
Early Educ Dev ; 29(1): 1-13, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29795975

RESUMEN

Positive emotional expressivity has been associated with increased social competence and decreased maladjustment in childhood. However, a few researchers have found null or even positive associations between positive emotional expressivity and maladjustment, which suggests that there may be nuanced associations of positive expressivity, perhaps as a function of the social context in which it is expressed. We examined whether observed positive emotional expressivity balance across peer-oriented/recreational and learning contexts predicted kindergarten children's adjustment (N = 301). RESEARCH FINDINGS: Higher positive expressivity during lunch/recess compared to positive expressivity in the classroom was associated with lower teacher-student conflict, externalizing behaviors, and depressive symptoms. In addition, overall positive emotional expressivity predicted lower externalizing behaviors as well as lower depressive and anxiety symptoms. PRACTICE OR POLICY: The results suggest the importance of assessing observed positive emotional expressivity in context as a potential indicator of children's maladjustment risk and the need for children to adapt their emotions to different contexts. Implications for assessing and supporting positive emotional expression balance and training emotional regulation in school are discussed.

6.
Early Educ Dev ; 29(7): 914-938, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-31997874

RESUMEN

This study evaluated the association between children's (N = 301) self-regulation and math and reading achievement in kindergarten, first grade, and second grade. Children's self-regulation was assessed using the Head-Toes-Knees-Shoulders (HTKS) task (involving control of gross body movements) and a computerized continuous performance task (CPT; assessing primarily inhibitory control) in kindergarten, first grade, and second grade. Research findings: Based on cross-lagged structural equation panel models, HTKS task performance positively predicted later math and reading achievement. Math achievement significantly and positively predicted later HTKS and CPT scores. Earlier math and reading achievement moderated the association between CPT scores and later math and reading achievement; inhibitory control-based self-regulation assessed with the CPT predicted higher math or reading achievement in subsequent grades for children with lower math or reading achievement in prior grades. Performance on the CPT moderated the paths from HTKS scores to later reading achievement; behavioral self-regulation assessed with the HTKS task predicted higher reading achievement in subsequent grades for children with low or average CPT performance in prior grades. Practice: Results from this study have the potential to inform targeted academic interventions focused on enhancing self-regulation in school contexts. The findings highlight the utility of assessing multiple measures of self-regulation.

7.
J Pers ; 86(5): 853-867, 2018 10.
Artículo en Inglés | MEDLINE | ID: mdl-29171879

RESUMEN

OBJECTIVE: We examined the relations of children's (N = 301) observed expression of negative and positive emotion in classes or nonclassroom school contexts (i.e., lunch and recess) to school adjustment from kindergarten to first grade. METHOD: Naturalistic observations of children's emotional expressivity were collected, as were teachers' reports of children's school engagement and relationship quality with teachers and peers. RESULTS: In longitudinal panel models, greater teacher-student conflict and lower student engagement in kindergarten predicted greater negative expressivity in both school contexts. School engagement and peer acceptance in kindergarten positively predicted first grade positive emotion in the classroom. Suggestive of possible bidirectional relations, there was also small unique prediction (near significant) from negative expressivity at lunch and recess to higher teacher-student conflict, from negative expressivity in the classroom to low peer acceptance, and from positive expressivity in the classroom to higher peer acceptance. CONCLUSIONS: The pattern of findings suggests that the quality of experience at school uniquely predicts children's emotional expressivity at school more consistently than vice versa-a finding that highlights the important role of school context in young children's emotionality at school.


Asunto(s)
Emociones/fisiología , Instituciones Académicas , Ajuste Social , Medio Social , Estudiantes/psicología , Niño , Preescolar , Femenino , Humanos , Masculino , Grupo Paritario
8.
Early Child Res Q ; 40: 98-109, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28684888

RESUMEN

This study evaluated the association between effortful control in kindergarten and academic achievement one year later (N = 301), and whether teacher-student closeness and conflict in kindergarten mediated the association. Parents, teachers, and observers reported on children's effortful control, and teachers reported on their perceived levels of closeness and conflict with students. Students completed the passage comprehension and applied problems subtests of the Woodcock-Johnson tests of achievement, as well as a behavioral measure of effortful control. Analytical models predicting academic achievement were estimated using a structural equation model framework. Effortful control positively predicted academic achievement even when controlling for prior achievement and other covariates. Mediation hypotheses were tested in a separate model; effortful control positively predicted teacher-student closeness and strongly, negatively predicted teacher-student conflict. Teacher-student closeness and effortful control, but not teacher-student conflict, had small, positive associations with academic achievement. Effortful control also indirectly predicted higher academic achievement through its positive effect on teacher-student closeness and via its positive relation to early academic achievement. The findings suggest that teacher-student closeness is one mechanism by which effortful control is associated with academic achievement. Effortful control was also a consistent predictor of academic achievement, beyond prior achievement levels and controlling for teacher-student closeness and conflict, with implications for intervention programs on fostering regulation and achievement concurrently.

9.
J Res Pers ; 67: 3-14, 2017 04.
Artículo en Inglés | MEDLINE | ID: mdl-28584388

RESUMEN

The current study examined the role of naturally-occurring negative and positive emotion expressivity in kindergarten and children's effortful control (EC) on their relationships with teachers, academic engagement, and problems behaviors in school. Further, the potential moderating role of EC on these important school outcomes was assessed. Emotion and engagement were observed at school. EC was assessed by multiple methods. Teachers reported on their student-teacher relationships and student's externalizing behaviors. Children's emotion expressivity and EC were related to engagement and relationships with teachers as well as behavioral problems at school. Children low in EC may be particularly vulnerable to the poor outcomes associated with relatively intense emotion expressivity as they struggle to manage their emotions and behaviors in the classroom.

10.
Int J Behav Dev ; 41(2): 275-284, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-28255190

RESUMEN

Poor sleep is thought to interfere with children's learning and academic achievement (AA). However, existing research and theory indicate there are factors that may mitigate the academic risk associated with poor sleep. The purpose of this study was to examine the moderating role of children's effortful control (EC) on the relation between sleep and AA in young children. One hundred and three 4.5- to 7-year-olds (M = 5.98 years, SD = 0.61) wore a wrist-based actigraph for five continuous weekday nights. Teachers and coders reported on children's EC. EC was also assessed with a computer-based task at school. Additionally, we obtained a standardized measure of children's AA. There was a positive main effect of sleep efficiency to AA. Several relations between sleep and AA were moderated by EC and examination of the simple slopes indicated that the negative relation between sleep and AA was only significant at low levels of EC.

11.
Int J Behav Dev ; 41(1): 30-40, 2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-28348445

RESUMEN

The purpose of the study was to evaluate bidirectional associations between peer acceptance and both emotion and effortful control during kindergarten (N = 301). In both the fall and spring semesters, we obtained peer nominations of acceptance, measures of positive and negative emotion based on naturalistic observations in school (i.e., classroom, lunch/recess), and observers' reports of effortful control (i.e., inhibitory control, attention focusing) and emotions (i.e., positive, negative). In structural equation panel models, peer acceptance in fall predicted higher effortful control in spring. Effortful control in fall did not predict peer acceptance in spring. Negative emotion predicted lower peer acceptance across time for girls but not for boys. Peer acceptance did not predict negative or positive emotion over time. In addition, we tested interactions between positive or negative emotion and effortful control predicting peer acceptance. Positive emotion predicted higher peer acceptance for children low in effortful control.

12.
Soc Dev ; 26(1): 21-39, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-29861553

RESUMEN

This study evaluated whether positive and anger emotional frequency (the proportion of instances an emotion was observed) and intensity (the strength of an emotion when it was observed) uniquely predicted social relationships among kindergarteners (N = 301). Emotions were observed as naturally occurring at school in the fall term and multiple reporters (peers and teachers) provided information on quality of relationships with children in the spring term. In structural equation models, positive emotion frequency, but not positive emotion intensity, was positively related to peer acceptance and negatively related to peer rejection. In contrast, the frequency of anger provided unique positive prediction of teacher-student conflict and negative prediction of peer acceptance. Furthermore, anger intensity negatively predicted teacher-student closeness and positively predicted teacher-student conflict. Implications for promoting social relationships in school are discussed.

13.
Emotion ; 16(4): 553-66, 2016 06.
Artículo en Inglés | MEDLINE | ID: mdl-26751629

RESUMEN

This study evaluated direct relations of both kindergarteners' (N = 301) naturalistically observed emotion in 2 different school contexts and early kindergarten verbal competence to academic adjustment (i.e., standardized measures of academic achievement, teacher-reported academic skills, teacher-reported and observed school engagement) and if these relations were mediated by teacher-reported conflict with students and by peer acceptance. When controlling for verbal competence, positive emotions expressed in the classroom context positively directly predicted academic skills, whereas positive emotions expressed outside class (lunch/recess) negatively predicted academic skills. Negative emotions observed in the classroom context and during lunch/recess negatively predicted academic achievement. Positive emotions observed in both contexts indirectly predicted higher school engagement through its positive relation to peer acceptance; positive emotions expressed in lunch and recess indirectly predicted higher school engagement via lower teacher-student conflict. Negative emotions observed in both contexts also indirectly predicted lower school engagement via higher teacher-student conflict. Furthermore, verbal competence indirectly predicted higher academic adjustment via lower teacher-student conflict. Moreover, verbal competence moderated the association between peer acceptance (but not teacher-student conflict) and academic adjustment. Because verbal competence moderated the associations from peer competence, positive emotions in both contexts indirectly predicted higher academic adjustment via higher peer acceptance primarily for children with low, but not high, initial verbal competence. (PsycINFO Database Record


Asunto(s)
Emociones/fisiología , Ajuste Social , Estudiantes/psicología , Preescolar , Femenino , Humanos , Relaciones Interpersonales , Masculino , Grupo Paritario , Instituciones Académicas
14.
Emotion ; 15(6): 699-704, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26214568

RESUMEN

The purpose of this study was to assess whether observed emotional frequency (the proportion of instances an emotion was observed) and intensity (the strength of an emotion when it was observed) uniquely predicted kindergartners' (N = 301) internalizing and externalizing problems. Analyses were tested in a structural equation modeling (SEM) framework with data from multireporters (reports of problem behaviors from teachers and parents) and naturalistic observations of emotion in the fall semester. For observed positive emotion, both frequency and intensity negatively predicted parent- or teacher-reported internalizing symptoms. Anger frequency positively predicted parent- and teacher-reported externalizing symptoms, whereas anger intensity positively predicted parent- and teacher-reported externalizing and parent-reported internalizing symptoms. The findings support the importance of examining both aspects of emotion when predicting maladjustment.


Asunto(s)
Emociones , Trastornos Mentales/psicología , Ajuste Social , Ira , Preescolar , Docentes , Femenino , Humanos , Masculino , Observación , Padres
15.
Dev Psychobiol ; 57(5): 596-606, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25939599

RESUMEN

We tested whether respiratory sinus arrhythmia (RSA) reactivity in response to each of three self-regulation tasks (bird and dragon; knock-tap; and gift wrap) would predict self-regulation performance in a sample of 101 preschool-age children (M age = 4.49, SD = .64). While controlling for baseline RSA, decreases in RSA from bird and dragon to knock-tap (but not from baseline to bird and dragon) predicted a latent variable measuring self-regulation. Furthermore, increases in RSA from the knock-tap to gift wrap-the only task involving delay of gratification-were related to concurrent task performance while controlling for the relation between RSA reactivity and the latent self-regulation variable. Results suggest that the relations between RSA reactivity and self-regulatory ability are influenced by task-specific demands and possibly by task order. Furthermore, RSA reactivity appears to relate differently to performance on motivationally salient self-regulation tasks such as delay of gratification relative to cool executive function tasks.


Asunto(s)
Hidrocortisona/fisiología , Arritmia Sinusal Respiratoria , Autocontrol , Preescolar , Femenino , Frecuencia Cardíaca/fisiología , Humanos , Masculino , Psicología Infantil , Frecuencia Respiratoria/fisiología , Arritmia Sinusal Respiratoria/fisiología , Autocontrol/psicología
16.
Dev Psychopathol ; 27(3): 709-23, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25159270

RESUMEN

We used sex, observed parenting quality at 18 months, and three variants of the catechol-O-methyltransferase gene (Val158Met [rs4680], intron1 [rs737865], and 3'-untranslated region [rs165599]) to predict mothers' reports of inhibitory and attentional control (assessed at 42, 54, 72, and 84 months) and internalizing symptoms (assessed at 24, 30, 42, 48, and 54 months) in a sample of 146 children (79 male). Although the pattern for all three variants was very similar, Val158Met explained more variance in both outcomes than did intron1, the 3'-untranslated region, or a haplotype that combined all three catechol-O-methyltransferase variants. In separate models, there were significant three-way interactions among each of the variants, parenting, and sex, predicting the intercepts of inhibitory control and internalizing symptoms. Results suggested that Val158Met indexes plasticity, although this effect was moderated by sex. Parenting was positively associated with inhibitory control for methionine-methionine boys and for valine-valine/valine-methionine girls, and was negatively associated with internalizing symptoms for methionine-methionine boys. Using the "regions of significance" technique, genetic differences in inhibitory control were found for children exposed to high-quality parenting, whereas genetic differences in internalizing were found for children exposed to low-quality parenting. These findings provide evidence in support of testing for differential susceptibility across multiple outcomes.


Asunto(s)
Catecol O-Metiltransferasa/genética , Función Ejecutiva/fisiología , Inhibición Psicológica , Responsabilidad Parental/psicología , Problema de Conducta , Regiones no Traducidas 3'/genética , Niño , Preescolar , Susceptibilidad a Enfermedades , Femenino , Genotipo , Haplotipos/genética , Humanos , Lactante , Intrones/genética , Masculino , Metionina/genética , Factores Sexuales , Valina/genética
17.
Soc Dev ; 23(3): 433-450, 2014 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-25346579

RESUMEN

We used observed parenting behaviors, along with genetic variants and haplotypes of the serotonin transporter gene (SLC6A4), as predictors of children's ego-resiliency during early childhood (N =153). Quality of mothers' parenting was observed at 18 months of age and mothers' reports of ego-resiliency were collected at six time points from 18 to 84 months. Genetic data were collected at 72 months. Observed parenting was positively associated with initial levels of children's ego-resiliency. Furthermore, although individual genetic variants of the serotonin transporter gene (LPR, STin2) were not associated with ego-resiliency, the S10 haplotype (that combines information from these two variants) was negatively associated with initial levels of ego-resiliency. Both parenting and serotonin genetic variation uniquely predicted children's ego-resiliency, suggesting an additive effect of genetic and parental factors.

18.
Biol Psychol ; 92(2): 241-8, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23127725

RESUMEN

Resting respiratory sinus arrhythmia (RSA) and shyness were examined as predictors of effortful control (EC) in a sample of 101 preschool-age children. Resting RSA was calculated from respiration and heart rate data collected during a neutral film; shyness was measured using parents', preschool teachers', and classroom observers' reports; and EC was measured using four laboratory tasks in addition to questionnaire measures. Principal components analysis was used to create composite measures of EC and shyness. The relation between RSA and EC was moderated by shyness, such that RSA was positively related to EC only for children high in shyness. This interaction suggests that emotional reactivity affects the degree to which RSA can be considered a correlate of EC. This study also draws attention to the need to consider the measurement context when assessing resting psychophysiology measures; shy individuals may not exhibit true baseline RSA responding in an unfamiliar laboratory setting.


Asunto(s)
Arritmia Sinusal , Frecuencia Cardíaca/fisiología , Respiración , Timidez , Controles Informales de la Sociedad/métodos , Niño , Preescolar , Emociones , Femenino , Juegos Experimentales , Fuerza de la Mano , Humanos , Conducta Imitativa , Masculino , Psicofísica , Descanso , Estadística como Asunto , Encuestas y Cuestionarios
19.
Dev Psychol ; 48(2): 552-66, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-22004341

RESUMEN

In a sample (n = 235) of 30-, 42-, and 54-month-olds, the relations among parenting, effortful control (EC), impulsivity, and children's committed compliance were examined. Parenting was assessed with mothers' observed sensitivity and warmth; EC was measured by mothers' and caregivers' reports, as well as a behavioral task; impulsivity was assessed by mothers' and caregivers' reports; and committed compliance was observed during a cleanup and prohibition task, as well as measured by adults' reports. Using path modeling, there was evidence that 30-month parenting predicted high EC and low impulsivity a year later when the stability of the outcomes was controlled, and there was evidence that 30- and 42-month EC, but not impulsivity, predicted higher committed compliance a year later, controlling for earlier levels of the outcomes. Moreover, 42-month EC predicted low impulsivity a year later. Fixed effects models, which are not biased by omitted time-invariant variables, also were conducted and showed that 30-month parenting still predicted EC a year later, and 42-month EC predicted later low impulsivity. Findings are discussed in terms of the importance of differentiating between effortful control and impulsivity and the potential mediating role of EC in the relations between parenting and children's committed compliance.


Asunto(s)
Desarrollo Infantil , Conducta Cooperativa , Control Interno-Externo , Conducta Materna , Relaciones Madre-Hijo , Madres/psicología , Factores de Edad , Preescolar , Femenino , Humanos , Conducta Impulsiva/psicología , Inhibición Psicológica , Estudios Longitudinales , Masculino , Modelos Psicológicos , Factores Sexuales , Conducta Social , Clase Social , Estadística como Asunto , Encuestas y Cuestionarios
20.
Dev Psychol ; 48(3): 740-54, 2012 May.
Artículo en Inglés | MEDLINE | ID: mdl-22059451

RESUMEN

The LPR and STin2 polymorphisms of the serotonin transporter gene (SLC6A4) were combined into haplotypes that, together with quality of maternal parenting, were used to predict initial levels and linear change in children's (N = 138) noncompliance and aggression from age 18-54 months. Quality of mothers' parenting behavior was observed when children were 18 months old, and nonparental caregivers' reports of noncompliance and aggression were collected annually from 18 to 54 months of age. Quality of early parenting was negatively related to the slope of noncompliance only for children with the LPR-S/STin2-10 haplotype and to 18-month noncompliance only for children with haplotypes that did not include LPR-S. The findings support the notion that SLC6A4 haplotypes index differential susceptibility to variability in parenting quality, with certain haplotypes showing greater reactivity to both supportive and unsupportive environments. These different genetic backgrounds likely reflect an evolutionary response to variation in the parenting environment.


Asunto(s)
Agresión/psicología , Trastornos de la Conducta Infantil , Conducta Materna , Repeticiones de Minisatélite/genética , Responsabilidad Parental/psicología , Proteínas de Transporte de Serotonina en la Membrana Plasmática/genética , Trastornos de la Conducta Infantil/etiología , Trastornos de la Conducta Infantil/genética , Trastornos de la Conducta Infantil/psicología , Preescolar , Salud de la Familia , Femenino , Frecuencia de los Genes , Pruebas Genéticas , Haplotipos , Humanos , Lactante , Estudios Longitudinales , Masculino , Modelos Estadísticos , Relaciones Madre-Hijo , Factores de Riesgo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...