Age-mate or twin sibling: Effects on interactions between monkey mothers and infants.

Examined the effects of the twin sibling relationship upon interactions between mother and infant. 12 rhesus monkey infants were reared with a mother and nonsibling peers; 8 had an age-mate or twin sibling, while 4 control infants did not. The sibling pairs were formed by fostering newborns 2 to a mother; the control infants were fostered 1 to a mother. Findings indicate that the twin infants did not engage in as much interaction with their mothers throughout a 7-mo period of observation on a wide range of indexes, including such basic behaviors as a contact with the mother's ventrum and nipples. The mothers rearing twins spent less time cradling their infants and less frequently rejected them. There were a few additional differences, notably in the area of restrictive behavior, but it is concluded that the differences in maternal behavior were principally a reaction to the differences in infant behavior. (27 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Development of a preferential relationship with the mother by the newborn lamb: importance of the sucking activity

Lambs develop a preferential relationship with their mothers within 24 h after birth. In a first experiment, we attempted to determine whether neonatal sucking was a potent reinforcer in the establishment of this preference by temporarily covering the udders of ewes after parturition. Lambs were assigned to one of three treatments: they had free access to the udder (group 1) or were prevented from sucking either between birth and 6 h afterward (group 2) or between 12 and 18 h after birth (group 3). Measurements of cholecystokinin plasma levels at birth and at 6 and 18 h showed that all lambs ingested some colostrum when the udder was made accessible. When tested in a two-choice test situation at 24 h of age, lambs from group 1 spent significantly more time near their mothers than near the alien ewes, those from group 2 did not show any discrimination, and lambs from group 3 clearly preferred the alien ewes. At 2 days of age, lambs from groups 1 and 3 showed a strong preference for their mothers, whereas those from group 2 still displayed no preference. In a second experiment, we attempted to determine whether sucking also had a reinforcing value in the maintenance of this preference. Lambs were assigned to one of three treatments: they had free access to the udder (group 1) or were prevented from sucking for 6 h either at birth (group 2) or at the age of 3 days (group 3). Lambs from group 2 did not discriminate between their own and alien dams when tested at 24 h of age, unlike those of groups 1 and 3. When a second test was performed at 4 days of age, all the lambs showed a strong preference for their dams. We concluded that sucking has strong rewarding properties in the establishment of a preferential relationship with the mother by the lamb. On the other hand, the maintenance of this preference does not rely on sucking as strongly.     

Sibling relationship quality from birth to adolescence: the enduring contributions of friends.

The purpose of the present study was to examine continuity in sibling relationships across childhood and to evaluate the degree to which children's experiences with their friends and mothers prior to their sibling's birth predict the quality of the relationship they establish with their siblings in adolescence. Twenty-eight firstborn children, who were 48 months old at the time of their sibling's birth, were observed interacting with their siblings and friends at multiple time points. The level of positive social behaviors demonstrated in their early relationships with friends continued to predict sibling relationship quality in adolescence. Firstborn children who had more positive interactions with friends prior to their sibling's birth demonstrated more prosocial interactions with both their siblings and friends in adolescence and exhibited fewer externalizing behaviors. Longitudinal associations support the hypothesis that the social competencies that young children demonstrate in their early relationships with friends may have enduring significance for their social development. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perceptions of parental and peer attachments by women with mood disorders.

The relationship between perceptions of parental and peer attachments at various ages and adult mood disorders was examined in 156 women classified as having bipolar disorder or unipolar depression or as nonpsychiatric controls. Nonpsychiatric controls reported a decreased attachment to their parents over time, but they also reported an increased closeness to their mothers in adulthood following a distant adolescence. Never hospitalized, moderately depressed Ss showed a similar trend toward decreased relatedness, but moderately depressed Ss did not report reestablishment of a close relationship with their mothers after adolescence. Severely depressed and bipolar Ss reported little attachment to their mother at all ages. Bipolar Ss also reported little connectedness to their fathers throughout their lifespan and severely depressed women felt less attached than nonpsychiatric controls to peers during development. None of the psychiatric groups reported difficulties with parental overcontrol. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Infant-mother recognition in a social rodent (octodon degus).

Octodon degus (degu), a biparental species with precocious offspring is a potential model for the study of social attachment and related affective disorders such as depression. This study investigates the nature of the social bond between young degus and their mothers with a special emphasis on infant-mother recognition. We tested young degus in a potentiation paradigm to determine if social contact, particularly with the mother, can modulate an infant's vocal response to isolation. One week later, animals were presented with a choice between their mother and an unfamiliar female or a sample of familiar and unfamiliar nesting materials. Subsequently, the ability of whole litters to discriminate between their mother and unfamiliar females was tested. We observed that infant degus alter their isolation response after brief social contact. Degu infants readily distinguish between familiar and unfamiliar nesting materials but fail to differentiate between their mother and unfamiliar females in an identical setting. Nevertheless, entire litters show a preference for their mothers when tested similarly in a group, demonstrating a perhaps socially facilitated ability to recognize the biological mother at an early age. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age-mate or twin sibling: Effects on monkey age-mate interactions during infancy.

12 rhesus monkey infants were reared with a mother and nonsibling peers; 8 had an age-mate or twin sibling, while 4 control infants did not. The twin sibling relationship was produced experimentally by pairing infants at birth and fostering them 2 to a mother; the control infants were also paired but fostered 1 to a mother. Positive affiliation with the paired rearing partner began earlier in the twin group and continued at higher levels throughout a 7-mo period of observation. The twins also engaged in more positive affiliation with age-mates other than the rearing partner, while the control infants more frequently engaged in solitary activities and displayed more aggressive and submissive behavior. It is concluded that the age-mate sibling had a beneficial effect upon early social development. (31 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Postpartum adjustment in first-time mothers: Relations between mood, maternal attitudes, and mother-infant interactions.

Self-report data were obtained from a middle-income sample of first-time mothers during pregnancy and at 1 and 3 months postpartum, and behavioral interactions between the mother and her infant were observed at 3 days and 1, 3, and 16 months postpartum. The main analyses revealed that pregnancy and postpartum mood states together explain a high proportion of the variance in mothers' maternal attitudes during the postpartum, although postpartum mood has the greater predictive power. Additionally, prior experience with children is significantly associated with maternal attitudes at all time points. Moreover, at both 1 and 3 months postpartum, depressed mothers, relative to nondepressed mothers, exhibit fewer affectionate contact behaviors toward their infants and are less likely to respond to infant vocalizations by vocalizing themselves, and, at 3 months, a higher proportion of the depressed mothers had started bottle-feeding their infants. Finally, differences in maternal behavior between depressed and nondepressed mothers during the early postpartum period were no longer apparent at 16 months postpartum. The implications of these findings are discussed with particular reference to the interrelations between prior child-care experience, mood, and maternal responsiveness. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Child temperaments, maternal differential behavior, and sibling relationships.

The primary purpose of this study was to examine the influence of two nonshared family environmental components—maternal differential behavior and sibling temperaments—on the sibling relationship of school-age children. Forty mothers and their same-sex children (20 pairs of boys and 20 pairs of girls) participated. In order to examine the associations of temperament and maternal differential behavior with the quality of sibling interactions, mothers were observed in triadic interactions with their two children. On a separate occasion the sibling dyad was observed interacting in the same contexts. The mothers also provided temperament ratings of each of their children's levels of activity, emotional intensity, and persistence. The results indicated that high activity, high emotional intensity, and low persistence levels in both older and younger children were associated with increased agonism between sisters, whereas high activity and low persistence levels for younger brothers were associated with more agonistic behavior among brothers. An imbalance of maternal behavior that favored the younger child was generally associated with lower rates of verbalizations and prosocial and agonistic behavior directed by siblings to one another. The observations of the mother–sibling triadic and sibling dyadic interactions also revealed consistency in the within-family environments. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Arguments and relationships within the family: Differences in young children's disputes with mother and sibling.

Examined whether children's arguments differ in disputes with mother and with sibling as well as how arguments used in family interaction relate to later assessment of social understanding. 50 children (aged 33 mo) were observed interacting with the mother and sibling in 2 visits in the child's home, and family conversation was recorded and subsequently transcribed. Results showed correlations between partners' arguments in conflict within dyads, but children's argument with their mothers was not related to that used when in dispute with their siblings. Children's use of argument with sibling was also predictive of sociocognitive performance assessed 7 mo later. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Indirect maternal effects of oxacillin administered to pregnant mice on the postnatal immune response of the offspring

Effects of oxacillin administered to pregnant or nursing randombred NMRI mice on the humoral immune response of their offspring were studied. The primary humoral response of male offspring to immunization by sheep red blood cells (SRBC) on the 24th postnatal day was assayed. Spectrophotometric determination of SRBC lysis by anti-SRBC IgM antibodies produced by spleen cells was used. Treatment of pregnant mice with oxacillin (70 mg/kg body weight) from the 12th to 16th day of pregnancy resulted in an enhancement of the spleen IgM antibody response in their offspring. The same treatment of nursing mothers, either on postnatal days 1-4 or 13-16, depressed the humoral response of the offspring. When the litters of control mothers and mothers treated with oxacillin from the 11th to 15th day of pregnancy were cross-fostered at birth, the offspring born of saline-treated mothers and nursed by oxacillin-treated mothers as well as the offspring born to oxacillin-treated mothers and nursed by control mothers produced significantly higher amounts of spleen anti-SRBC IgM than the control offspring. The results suggest that the alteration of the immune response in offspring of mice treated by oxacillin during pregnancy was induced not only in the prenatal period, but also postnatally by factors originating from effects of oxacillin on the maternal organism.     

Genetic and environmental influences on maternal and sibling interaction in middle childhood: A sibling adoption study.

Genetic and environmental influences on maternal and sibling interactions were examined in 67 mother–child–child triads from nonadoptive families and 57 mother–child–child triads from adoptive families (in which both children were adopted and genetically unrelated). Triads were videotaped in 6 play settings in their homes. In addition, each sibling pair was observed in an unstructured setting in the home, and mothers completed an interview about the sibling relationship. Genetic influence was found for individual differences in sibling interactions (competition and positive and negative behavior) and maternal interactions with siblings (maternal attention and control); shared environmental factors were also important. No evidence was found for mean differences between the adoptive and nonadoptive families that could be due to genetic influence; family constellation factors also were not important. Results are discussed with respect to genetic influences on family interactions and relationships. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Conversations with mothers and siblings: Young childrens' semantic and conceptual development.

This study compared teaching and learning measures of 16 mother–child and sibling dyads playing a picture categorization game. Target children (mean age?=?3 years 11 months) participated in 2 separate sessions, 1 with their mother and 1 with their older sibling (mean age?=?6 years 11 months). Although siblings' teaching styles directed target children to make the correct choices, mothers provided information to help target children make choices on their own. Mothers labeled objects and categories more than siblings. Although target children scored higher with siblings than with mothers, this was because siblings categorized about half of the pictures themselves. Target children labeled objects and categories more with mothers than with siblings. These findings suggest important differences in how mothers and siblings interpreted the goals of the task, offering target children different teaching styles from which to learn. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Impact of premature birth on the development of the infant in the family.

This article describes effects of the birth of a premature infant on the family system and focuses on how problems associated with premature birth such as infant illness, hospitalization, and immaturity can place the family at risk. New data are presented describing differences in the behavior of preterm and full-term infants and in the feelings of mothers toward their infants at 12 months. Mothers of preterm infants reported feeling overprotective toward them, were less willing to leave them with sitters, and believed that their birth had an initially negative effect on the family. Preterm infants showed less exploratory play and stayed closer to their mothers during free play. The fact that these differences are not reflected in patterns of attachment, a key measure of the mother–infant relationship, is discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Depression in first-time mothers: Mother-infant interaction and depression chronicity.

Married, middle-class women who met diagnostic criteria for depression and a comparable group of nondepressed women were videotaped interacting with their infants at home at 2, 4, and 6 months. When depression was defined in terms of 2-month diagnosis, there were no differences between depressed and comparison mothers or babies in either positive or negative interaction during feeding, face-to-face interaction, or toy play. However, women whose depressions lasted through 6 months were less positive with their infants across these 3 contexts than women whose depressions were more short-lived, and their babies were less positive during face-to-face interaction. These data highlight the need to distinguish between transient and protracted depression in evaluating depression effects on the mother–infant relationship and infant outcome. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sibling quarrels and maternal responses.

Examined 40 mothers' interventions in their children's quarrels at 2 time points: when the second-born child was 8 and 14 mo old. Firstborn boys showed more frequent hostile behavior at 14 mo if their mothers had, 6 mo earlier, intervened in a high proportion of quarrels by prohibiting the boys. In families with firstborn girls, in contrast, a high frequency of sibling quarrels at 8 mo was correlated with a high frequency of maternal prohibition 6 mo earlier. Mothers of boys were significantly more consistent in their response to hostile behavior than were mothers of girls. The age of the firstborn was positively correlated with the proportion of quarrels in which the mother prohibited the firstborn and was negatively correlated with the proportion in which she used distraction techniques. (25 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Antecedents and consequences of boys' depression and aggression: Family and school linkages.

This study, conducted with 246 mothers and sons, examined the influences of change in marital conflict and mother–son aggression on boys' aggression and depression and how boys' aggression and depression contributed to their being disliked by their peers. There was also interest in how boys' family and peer experiences contributed to their subsequent behavior. Boys who experienced increases in marital conflict were more depressed, whereas boys who experienced negative interactions with their mothers were more aggressive. Boys who were either depressed or aggressive were more disliked by their peers, and being disliked was associated with aggressive behavior subsequently. However, being depressed appeared to attenuate the negative effect of being disliked by one's peers. The association between boys' earlier aggression and their subsequent aggression with their peers was mediated by dislike by their peers. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of early maternal employment on toddlers, mothers, and fathers.

Investigated the effects of early maternal employment on toddler development and mothers' and fathers' parenting styles using a family system orientation. The 75 families with firstborn 20-mo-olds varied in maternal employment status (nonemployed, part-, and full-time). Observations were conducted of qualitative dimensions of parent–child relationships (toddler–mother and toddler–father attachment and child–parent problem-solving behavior), quantitative dimensions of family time allocation, and parental childrearing attitudes. Each mother had been employed outside the home prior to the baby's birth. 24 mothers had not been employed since the birth of their children; 23 mothers were employed part-time. Results indicate that maternal employment was not related to toddler outcomes (security of attachment or problem-solving behavior). It was related to the amount of time mothers spent with their children and to some childrearing attitudes and behaviors of fathers and mothers. Findings highlight the importance of examining direct (mother–child) and indirect (father–child) effects in the study of early maternal employment and the ability of families to adapt to a variety of lifestyles. (24 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Mothers' perceptions of sibling adjustment and family life in childhood chronic illness

Researchers who study the effects of chronic illness on well siblings have generally focused on individual characteristics and their relationships with psychological adjustment. More recently, researchers suggest that sibling adjustment can be best understood within the context of the family. The purpose of this study was to examine variations in sibling behavioral adjustment in relation to mothers' perceptions of the illness experience and family life. Based on mothers' ratings on the behavior problem scale of the Child Behavior Checklist (CBCL), five siblings considered poorly adjusted and five very well-adjusted siblings were compared with respect to mothers' reports of individual family member's response to illness, illness management, parenting philosophy, presence of other stressors, availability of social supports, and impact of illness on family members and family life. Two major differences were found between mothers who rated healthy siblings either poorly or very well adjusted: (a) effects of illness on the healthy sibling, the ill child, and the marital relationship and (b) perceived controllability of the chronic illness. Devising ways of helping mothers feel confident in managing their child's illness is integral to creating an environment that promotes optimal development of their ill child and the child's siblings.     

Les effets de la dépression maternelle sur la relation mère-enfant au cours des trois premières années de vie: état de la recherche actuelle et analyse critique.

Notes that many mothers with young children experience depression. The goal of this paper is to describe and analyze the empirical evidence emerging from studies that have examined the impact of maternal depression on mother–infant relationship during the first 3 year period following birth. These empirical studies have reviewed a wide range of variables related to the relational dynamic between the depressed mother and her infant, including mother's and infant's factors (behaviors, affects, mood, perceptions, physiological and biochemical measures), and components of the quality of the relationship (behavior–state matching, synchrony, mother–infant attachment). These studies lead to different, and often contradictory, conclusions. The potential causes of this disparity are examined in the context of the diversity of theoretical conceptions and methodologies as well as limitations that were inherent in the studies. It is argued that an integrated model of the various factors reviewed in this paper is needed to help understand the impact of maternal depression on mother–infant relationship. (PsycINFO Database Record (c) 2010 APA, all rights reserved)