Temperament profiles from infancy to middle childhood: development and associations with behavior problems

The authors applied I-States as Objects Analysis (ISOA), a recently proposed person-oriented analytic approach, to the study of temperament development in 921 Norwegian children from a population-based sample. A 5-profile classification based on cluster analysis of standardized mother reports of activity, sociability, emotionality, and shyness at ages 18 months, 30 months, 4-5 years, and 8-9 years was interpretable and highly replicable. The prevalence of temperament profiles changed markedly with age, and individual stability in temperament profiles was significant. Specific typical and atypical developmental sequences of profiles were identified. Selective patterns of concurrent group differences in externalizing and internalizing problems by temperament profiles were remarkably similar across ages. The findings to some degree support the notion that individual temperament-variable values take on meaning in relation to the whole individual configuration and indicate some lawfulness in temperament changes over time. Future person-oriented studies of temperament development should replicate the current results using multiple data sources, rigorous tests of gender differences, and latent group modeling. (PsycINFO Database Record (c) 2008 APA, all rights reserved).     

Hand preference as related to development and behavior in infancy

55 healthy infants were assessed for their developmental and behavioral patterns at the age of 9 mo. Hand preference was assessed at 20 mo. of age. The distribution of hand preference showed 12 were right-handed, 11 left-handed and 23 ambidextrous. This distribution appears shifted more to the left than that reported for older children. Although their data were based on different tests not appropriate for 9-mo.-old infants, ambidexterity appeared to reflect part of the hand-preference continuum. No significant relationship between hand preference and developmental attainments was noted. Perhaps a larger sample would provide a clear developmental behavioral pattern and hand preference in infancy.     

Changes in imitative behavior during early infancy

Changes in imitative behavior and attentiveness were observed in 40 infants when they were 2 to 6 months of age. The facial expressions happy, sad, and surprised were modeled in a trials-to-criterion procedure, and the infants' looking time and mouth movements were recorded by an observer who was unaware of the face being modeled. In addition, the observer recorded her guess as to the expression being modeled by the corresponding expression on the infant's face and rated the infant's expressivity. The results suggested that looking time, correspondence between the mouth expression of the infant and the mouth expression modeled, accuracy of the observer's guess, and expressivity ratings decreased from 2 to 3 and 4 to 6 months. Although matching of mouth movements with the modeled mouth movements and accuracy of guesses were greater than chance over the 2 to 6 month-period, the decreases in these measures suggest that imitative behavior declined across early infancy. The decrease in looking time suggests that imitative behavior and attentiveness may be related and highlights the limitation of this paradigm for assessing the development of imitation during early infancy.     

A longitudinal twin study of the genetic and environmental etiology of maternal hostile-reactive behavior during infancy and toddlerhood

Children's negative characteristics are thought to be a factor in evoking hostile parenting responses. This can result in genotype/environment correlations (rGE) in which children's heritable traits influence the parenting they experience. We did genetic analyses on 292 mothers' self-reported hostile-reactive behaviors toward each of their twins at 5, 18 and 30 months. Finding heritability for a parenting behavior analyzed as a child phenotype is evidence of rGE correlation. The heritability of maternal behavior was modest (29% at 5 months, 0% at 18 months, and 25% at 30 months) and longitudinal analyses indicated that genetic factors at 5 and 30 months were uncorrelated. Common environment factors, probably reflecting characteristics of the mothers, were the main source of variance at the three ages and were highly correlated through time. We concluded that children's heritable characteristics evoked maternal negative response at specific times, but were not responsible for the stability of maternal hostility from infancy to toddlerhood.     

Hysterectomy-induced maternal behavior during pregnancy in the rat.

Hysterectomies were performed between the 10th and 19th day of pregnancy, and females were tested with pups for the onset of maternal behavior starting 0,24, 48, or 72 hr after surgery. Pups remained with the females overnight, and testing was repeated daily with fresh pups until females exhibited maternal behavior. Latencies for the onset of maternal behavior were shorter after hysterectomy on the 10th and 16th days of pregnancy than in intact pregnant females at the same stages of pregnancy; latencies became shorter, the later the termination of pregnancy. When the ovaries were removed along with hysterectomy during pregnancy, short-latency maternal behavior no longer was exhibited. Pregnant females were tested during the last 40 hr of pregnancy: nest building began at 34 hr prepartum and retrieving at 28 hr prepartum. The effect of hysterectomy during pregnancy on ovarian secretion of estrogen and progesterone is reviewed, and it is concluded that the rise in estrogen secretion, which follows hysterectomy during pregnancy, is most likely the cause of the rapid onset of maternal behavior after hysterectomy. A similar proposal is made for the prepartum onset of maternal behavior in intact pregnant females.     

Positive maternal interaction behavior moderates the relation between maternal anxiety and infant regulatory problems

Regulatory problems in infancy are determined by different risk factors. This study aims to examine how psychosocial risk factors are connected, and how they impact the early regulatory ability of 3-month-old infants. In a sample of 57 mother–infant dyads, maternal anxiety and infant crying, sleeping and feeding habits were assessed. As a possible moderator, the role of positive maternal behavior was analyzed by videotaping face-to-face interactions. During the interaction, interactive stress was provoked with the face-to-face still-face paradigm (FFSF). Thus, this study differentiated between the effects of maternal behavior in both an ordinary play context, as well as a stressful interaction context. Results revealed that the relation between maternal anxiety and infant regulatory problems in crying and sleeping varied as a function of positive maternal engagement in stressful situations. However, a significant moderation effect influencing infant feeding problems could not be demonstrated. These findings stress the importance of positive maternal interaction behavior in at least some parts of regulatory adjustment of at-risk infants.     

The development of anticipatory hand orientation during infancy

The development of infants' prehensile adjustments regarding the orientation of objects was investigated. Five- and nine-month-olds (N = 16 per group) were presented with horizontally and vertically oriented dowels to determine at what point during the reach, hand orientation approximated that of the dowel. Nine-month-olds rotated their hands appropriately, early in the course of the reach, i.e., before tactual contact of the dowel, whereas five-month-olds did so mostly after tactual contact. Analyses of the effects of trials within the experimental session indicated that this age difference was not associated with practice or fatigue effects. The results are discussed in relation to the development of visual control of prehensile behavior.     

Maternal responsiveness to infant Norway rat (Rattus norvegicus) ultrasonic vocalizations during the maternal behavior cycle and after steroid and experiential induction regimens

When removed from the nest and placed in a cool environment, Norway rat (Rattus norvegicus) pups emit ultrasonic vocalizations that can elicit maternal search behavior. The authors examined the behavior of pregnant dams, mothers, and virgin females during exposure to a pup that was either warm and silent or cool and vocalizing. Results indicate potentiated maternal reactions to a vocalizing pup: Mothers approached and maintained proximal orientation to a vocalizing pup far more than did virgin females. Elevated levels of proximal orientation appeared within hours of birth, increased during the 1st week postpartum, and declined by the time of weaning. Estrogen plus progesterone administration facilitated virgin females' proximal orientation toward vocalizing pups, whereas prolonged exposure to pups in the absence of hormones was without effect, suggesting that the ontogeny of the maternal response is regulated, at least in part, by maternal hormones.     

Perceived social support and maternal adaptation during the transition from hospital to home care of high-risk infants

Forty-two mothers of high-risk infants who had been hospitalized in a newborn intensive care unit were interviewed approximately 2 months after hospital discharge. On standard questionnaires, they reported how much support they had received since discharge and their need for and satisfaction with support in three areas: Emotional, informational, and tangible support. Mothers also completed the Profile of Mood States, the Sleep, Feeding, and Crying Questionnaire, and the Impact of Event Scale and rated the severity of the infant's medical condition and expected developmental/health outcome. Measures of maternal adaptation and infant characteristics were subjected to exploratory factor analysis from which summary scores were constructed. One maternal adaptation factor and two infant status factors were examined in relation to social support variables, but no significant associations were found for the sample as a whole. However, satisfaction with each area of support was related to maternal adaptation when the infant's post-discharge status was relatively more severe. The results are discussed in terms of the crises of the hospital to home transition and the difficult tasks that face parents after the assumption of full responsibility for a vulnerable infant who required newborn intensive care.     

Prepartum and postpartum open-field behavior and maternal responsiveness in mice bidirectionally selected for open-field thigmotaxis

The authors examined pre- and postpartum open-field (OF) behavior and maternal responsiveness in mice that they bidirectionally selected for OF thigmotaxis. The authors tested 40 female mice under 3 conditions: prepartum OF, postpartum OF, and a pup retrieval test. In both OF conditions, the high OF thigmotaxis (HOFT) mice were more thigmotactic but explored and reared less than the low OF thigmotaxis (LOFT) mice, indicating that the HOFT mice were more emotional. In the postpartum condition, the HOFT mothers also defecated more and ambulated less than the LOFT mothers. The increase in grooming after parturition was more conspicuous among the LOFT mothers than among the HOFT mothers. The LOFT mothers were also more attracted to their pups in the OF, but the retrieval test did not show any substantial line differences. The results suggested that the line difference in emotionality was more pronounced during lactation than during pregnancy, although parturition exerted no effect on thigmotaxis.     

Predicting stability and change in toddler behavior problems: contributions of maternal behavior and child gender

This study examined the stability and continuity of early-identified behavior problems and the factors associated with this stability. Children and their mothers (N=125) were seen when the children were 2 and 4 years of age. Maternal reports of child externalizing behavior and laboratory observations of child noncompliance were stable from age 2 to age 4. Early externalizing behaviors decreased over time; however, child noncompliance in the laboratory did not. Although few associations were found between maternal positive behavior and child behavior problems, maternal controlling behavior was related to increases in child behavior problems, particularly at high levels of both prior noncompliance and prior maternal control. Child noncompliance was predictive of increases in maternal controlling behavior over time.     

Infant responsiveness and maternal confidence in the neonatal period

Responsiveness in prematurely and term-born infants was studied cross-sectionally in relation to maternal confidence. Orientation and arousal were measured in 140 prematurely (mean BW 1,398 g, GA 30.1 weeks) and 75 term-born infants (mean BW 3,613 g, GA 39.3 weeks) with the Neonatal Behavioral Assessment Scales. Mothers filled out the Maternal Confidence Questionnaire and a modified version of the Parenting Stress Index. Prematurely born infants had a significantly lower level of arousal than term-born neonates. Responsiveness was not associated with maternal confidence. Lower confidence was associated with primiparity in both groups of mothers. Multiparous mothers of prematurely born infants had significantly lower levels of confidence than multiparous mothers of term-born infants. Confidence was significantly associated with stress for mothers of prematurely and term-born infants, and may be focused in follow-up after giving birth. Prematurely born infants should be examined more thoroughly in aspects of arousal at the time of discharge.     

The relationship of parental warm responsiveness and negativity to emerging behavior problems following traumatic brain injury in young children

Parenting behaviors play a critical role in the child's behavioral development, particularly for children with neurological deficits. This study examined the relationship of parental warm responsiveness and negativity to changes in behavior following traumatic brain injury (TBI) in young children relative to an age-matched cohort of children with orthopedic injuries (OI). It was hypothesized that responsive parenting would buffer the adverse effects of TBI on child behavior, whereas parental negativity would exacerbate these effects. Children, ages 3-7 years, hospitalized for TBI (n = 80) or OI (n = 113), were seen acutely and again 6 months later. Parent-child dyads were videotaped during free play. Parents completed behavior ratings (Child Behavior Checklist; T. M. Achenbach & L. A. Rescorla, 2001) at both visits, with baseline ratings reflecting preinjury behavior. Hypotheses were tested using multiple regression, with preinjury behavior ratings, race, income, child IQ, family functioning, and acute parental distress serving as covariates. Parental responsiveness and negativity had stronger associations with emerging externalizing behaviors and attention-deficit/hyperactivity disorder symptoms among children with severe TBI. Findings suggest that parenting quality may facilitate or impede behavioral recovery following early TBI. Interventions that increase positive parenting may partially ameliorate emerging behavior problems.     

Perioral anesthesia disrupts maternal behavior during early lactation in Long-Evans rats

The role of perioral somatosensory stimulation from pups in maternal behavior was investigated in lactating Long-Evans rats (Rattus norvegicus) during early lactation by local anesthesia of the mystacial pads with lidocaine, which blocks conduction in the infraorbital nerve. It was concluded that (1) acute perioral anesthesia markedly inhibited pup retrieval when the subjects had no formal pretreatment retrieval experience. Further, these dams displayed little tolerance to the lidocaine treatment when they were tested repeatedly. (2) The severity of the effects of perioral anesthesia on retrieval was dependent upon prior experience and the testing situation. Following pretreatment retrieval experience, and in a test cage with dark and light compartments which provided a strong incentive to retrieve, 80% of lidocaine-injected dams did retrieve. However, retrieval efficiency was impaired by perioral anesthesia, largely due to increased time in contact with pups prior to each retrieval and to increased carrying time. (3) Perioral anesthesia also inhibited pup licking, but not self-grooming, suggesting that the former, but not the latter, is largely under peripheral stimulus control and that deficits in maternal oral activities cannot be due to impairment of mouth opening and use. (4) The onset of nursing behavior was delayed until after the recovery of snout sensations and retrieval. This suggests that a maternal behavior not directly involving the mouth is nonetheless dependent upon the dam's receipt of perioral tactile input from pups.     

The mediating role of maternal responsiveness in some longer term effects of postnatal depression on infant development

We hypothesized a mediating role for low maternal responsiveness in certain child developmental deficits found previously to be associated with postnatal depression. Forty depressed inpatients and 48 control (non-depressed) mothers and their infants were followed until 42 months postpartum. Mother–infant interactions were impaired at 6 months postpartum in the depressed group. Subsequent cognitive deficits were found in children's Full Scale IQ on the Wechsler Preschool Primary Scale of Intelligence (Revised) at 42 months of age. Statistical modeling of the mediation hypothesis confirmed that these effects were overwhelmingly explained by lowered maternal responsiveness at 6 months. Similarly, increased temperamental difficulties were apparent in children of depressed mothers but were not correlated with maternal responsiveness. Male infants of depressed mothers were disproportionately vulnerable (compared to females) to impaired cognitive abilities associated with maternal depression. The data concur with previous work and provide empirical support for the theoretical prediction that early disturbances of the mother–infant interaction will mediate some developmental deficits in the children of depressed mothers.     

The development of concern for others in children with behavior problems

The development of concern for others and externalizing problems were examined in young children with normative, subclinical, or clinical levels of behavior problems. There were no group differences in observable concern for others at 4-5 years of age. Children with clinical behavior problems decreased significantly in their concern by 6-7 years of age and were reported to have less concern at 6-7 years by mothers, teachers, and the children themselves, relative to other groups. Boys with clinical problems were more callous to others' distress at both time points. Girls showed more concern than boys across risk, time, and measures. Greater concern at 4-5 years predicted decreases in the stability and severity of externalizing problems by 6-7 years, and greater concern at 6-7 years predicted decreases in the stability of problems by 9-10 years. Finally, maternal socialization approaches predicted later concerned responding.