Infant crying and parent–infant interaction: Theory and measurement

Infant crying is frequently quantified as a primary dependent variable in studies where the goal is to understand and soothe infant crying within the context of the parent–infant relationship. Through a historical review and an examination of studies and measurement techniques, the utility of quantifying infant crying is discussed. Although duration and timing of infant crying may be a practical concern for families and health professionals, the effectiveness of soothing interventions may not be best examined by attempts to measure unit reductions in infant crying. Rather, developing an understanding of infant crying within the context of parent–infant relationships may have more utility. Understanding infant crying in context may provide direction to the selection of soothing interventions and to more appropriate measures of the effectiveness of such interventions. ©1999 Michigan Association for Infant Mental Health.     

When soothing succeeds: Simulating a risk for repeated shaking in abusive head trauma in infants

PurposeTo investigate the observation that perpetrators of abusive head trauma engage in repeated shakings because shaking “works” to quiet the infant.MethodsSixty first-time parent couples individually cared for a programmable model infant in two consecutive 7-min trials. After six minutes of consolable followed by inconsolable crying, parents selected one of three soothing techniques. For trial one, parents were randomized to a “Successful” or “Failed” Soothing Condition. Whether the soothing technique was repeated after trial two was determined by the study investigators. Parents rated their frustration after each trial.ResultsAs hypothesized, parents were more likely to repeat a soothing technique that “worked” in trial one. Compared to fathers, mothers reported more frustration when soothing failed.ConclusionsThat caregivers were more likely to repeat a successful soothing technique converges with perpetrator confessions that crying cessation after shaking may be a reason why shaking is used repeatedly in response to crying.     

Effectiveness of Primiparae and Multiparae at Soothing Their Newborn Infants

To examine the effectiveness of new parents at soothing their infants, the authors filmed primiparae (20 mothers, 20 fathers) and, for comparison, multiparae (25 mothers, 25 fathers) during an interaction with their crying 2- to 3-day-old infants. Data were derived from loudness ratings of the infants' distress signals and by measuring the time it took parents to quiet their infants. In addition, specific parental behaviors were coded by microanalysis. From these data, measures of soothing effectiveness and behavioral profiles were derived. Data analyses showed that most primiparae were effective at soothing their infants' cries and that there were no parity effects on measures of soothing effectiveness. However, mothers, regardless of parity, were more effective at quieting their infants than were fathers, and there were significant differences in mothers' and fathers' caregiving behaviors. These data suggest that primiparae are effective at quickly soothing their newborns and that their skill, as measured, does not depend on parenting experience. Moreover, the data point to significant differences in mothers' and fathers' competence at quieting their newborns whether or not they are experienced at parenting.     

The signal functions of early infant crying

In this article I evaluate recent attempts to illuminate the human infant cry from an evolutionary perspective. Infants are born into an uncertain parenting environment, which can range from indulgent care of offspring to infanticide. Infant cries are in large part adaptations that maintain proximity to and elicit care from caregivers. Although there is not strong evidence for acoustically distinct cry types, infant cries may function as a graded signal. During pain-induced autonomic nervous system arousal, for example, neural input to the vocal cords increases cry pitch. Caregivers may use this acoustic information, together with other cues, to guide caregiving behavior. Serious pathology, on the other hand, results in chronically and severely abnormal cry acoustics. Such abnormal crying may be a proximate cause of adaptive infant maltreatment, in circumstances in which parents cut their losses and reduce or withdraw investment from infants with low survival chances. An increase in the amount of crying during the first few months of life is a human universal, and excessive crying, or colic, represents the upper end of this normal increase. Potential signal functions of excessive crying include manipulation of parents to acquire additional resources, honest signaling of need, and honest signaling of vigor. Current evidence does not strongly support any one of these hypotheses, but the evidence is most consistent with the hypothesis that excessive early infant crying is a signal of vigor that evolved to reduce the risk of a reduction or withdrawal of parental care.     

Effectiveness of primiparae and multiparae at soothing their newborn infants

To examine the effectiveness of new parents at soothing their infants, the authors filmed primiparae (20 mothers, 20 fathers) and, for comparison, multiparae (25 mothers, 25 fathers) during an interaction with their crying 2- to 3-day-old infants. Data were derived from loudness ratings of the infants' distress signals and by measuring the time it took parents to quiet their infants. In addition, specific parental behaviors were coded by microanalysis. From these data, measures of soothing effectiveness and behavioral profiles were derived. Data analyses showed that most primiparae were effective at soothing their infants' cries and that there were no parity effects on measures of soothing effectiveness. However, mothers, regardless of parity, were more effective at quieting their infants than were fathers, and there were significant differences in mothers' and fathers' caregiving behaviors. These data suggest that primiparae are effective at quickly soothing their newborns and that their skill, as measured, does not depend on parenting experience. Moreover, the data point to significant differences in mothers' and fathers' competence at quieting their newborns whether or not they are experienced at parenting.     

Effects of massage intervention on discharged premature infants’ weight,parental stress,and parent–child attachment: A randomized controlled trial

Infant massage enhances the growth and development of premature infants and promotes parent–child bonding. However, its effects on parental stress and parent–child attachment in premature infants, as well as gender differences thereof, remain unclear. In this randomized controlled trial, we used a repeated-measures design and included 61 premature infants (mean gestational age: 35.1 ± 1.5 weeks). Weight, parental stress, and parent–child attachment were measured at multiple time points: before massage and 1, 4, 8, and 12 weeks after commencing infant massage. The results revealed that the massage group infants had significantly higher weight gain than the control (no massage) group infants at all four time points. Moreover, parents in the massage group reported notably lower levels of stress than those in the control group, particularly in the parental distress and difficult children subscales. No significant between-group differences were observed in parent–child attachment. Furthermore, no significant differences were observed between fathers and mothers in parental stress and parent–child attachment. However, fathers reported higher levels of distress than mothers at 4 and 12 weeks. In conclusion, infant massage led to increased infant weight and reduced parental stress over time, and differences between fathers and mothers were not significant, except fathers exhibiting higher levels of distress than mothers over time. Healthcare professionals should educate and support parents on infant massage before discharge of premature infants.     

Effects of Early Parenting Interventions on Parents and Infants: A Meta-Analytic Review

This systematic review evaluates the efficacy of parenting interventions on parent, infant and parent-infant relationship outcome measures for parents of infants under 12 months old. Parent outcomes examined included competence, and confidence; baby outcomes included infant behaviours of crying, settling, and sleeping problems and parent-infant relationship outcomes included parental responsiveness. Systematic searches of five databases were carried out. In total, 36 randomised controlled trials over the past 35 years were included in the meta-analyses, with a total of 4880 participants. Interventions were carried out either during pregnancy or within the first 12 months after birth and involved teaching specific strategies and provision of information on infant development and behaviour. Mean effect sizes were obtained using a structural equation modelling (SEM) approach to meta-analysis. Heterogeneity was found on parent responsiveness and infant sleep. Potential moderator variables were assessed for these two outcomes using the SEM approach. Results showed that early parenting interventions are effective in improving parental responsiveness (d?=?0.77), and improving or preventing infant sleep problems (d?=?0.24), but not crying problems (d?=?0.27) possibly due to low power. No conclusions could be drawn in regards to parental competence or confidence. Moderator analysis showed that for interventions aimed at improving responsiveness, briefer interventions were more effective than longer ones; and studies published more recently reported smaller effects than older studies. No other moderators influenced the assessed intervention outcomes. The findings of this study provide further evidence for the positive effects of early parenting interventions for infants under 12 months of age, however future research is needed to assess intervention effects on parental competence and confidence.     

Infantile colic and parental experiences

The study comprised two groups of 33 parents each, one whose infants were identified by parents as colicky during their first 3 months and one with non-colicky infants. Parents filled out a questionnaire with one set of questions about parental experiences when infants were 3 months old and a set of parallel questions concerning current experiences (infant age 8-11 months). The results showed that the 3-month situation was more negatively described with regard to both infant behaviour and parental experiences by the parents of colicky infants. For the current situation (8-11 months), there were no significant group differences, meaning that no long-lasting effects could be demonstrated. However, in the colic group amount of crying and difficulty in comforting during the colic period were significantly related to current parental satisfaction, which suggests that these aspects of infant behaviour and experienced parental competence are of importance also in a longer perspective.     

The relation between 3‐ and 15‐month olds' cry vocalizations and their mothers' affective involvement during inoculation

This study examined if infant immunization distress is related to their mothers' affective involvement prior to the injection. The duration of infant cry vocalizations and the amount of maternal behaviour before and after the syringe injection were observed in 18 mother–infant dyads, of whom nine comprised 3‐month‐old and nine 15‐month‐old infants. The maternal behaviour was scored in terms of various soothing strategies used to calm infants in distress. Infant cry duration, in both the 3‐ and the 15‐month olds, was associated with amount of maternal eye‐gaze before the injection. For the 15‐month olds, also face‐to‐face contact and rocking the infant was associated with more crying. Even though the small scale of the study warrants some caution in the interpretation, the overall findings suggest that young infants have a referential understanding of caregiver affective involvement prior to a stressor. Copyright © 2007 John Wiley & Sons, Ltd.     

Maternal soothing and infant stress responses: soothing, crying and adrenocortical activity during inoculation

The relation between maternal soothing and infant stress response during inoculation was examined in a sample of 37 mothers and their 3-month-old infants. The mothers' soothing and the infants' cry vocalizations and the mothers' and the infants' salivary cortisol level pre- and post-injection were analysed. There was a positive relation between infants' cry vocalization post-injection and maternal soothing pre- and post-injection. The sample was divided in two sub-groups depending on whether the mothers evidenced most soothing of the infants in the period before (Preparatory group; n=20) or after (Contingent group; n=17) the syringe injection. In the Preparatory group, the duration of infant cry vocalizations was related to amount of maternal soothing before and after the injection, while cry vocalizations in the Contingent group was related to amount of maternal soothing after the injection. The Contingent infants responded to the injection with a significant increase in cortisol, while there was no increase in the Preparatory infants. The Preparatory infants evidenced significantly longer duration of looking at the target stimuli in a visual marking task, suggesting greater difficulties in disengaging attention. These findings indicate that 3-month-olds' stress responses and their mothers' situational behaviour are mutually regulated.     

Clinical,developmental and social aspects of infant crying and colic

Persistent unexplained infant crying in the first few months is a common source of distress for parents and is costly for the health services. The aim was to assess the merits of developmental and social conceptualizations of this phenomenon, compared to the clinical approach as represented by the concept of colic. From a community sample of 530 infants, 67 who met the ‘rule of threes’ definition of colic by fussing and crying for 3 or more hours per day at 4-5 weeks of age were chosen. To avoid confusion, these infants were called ‘persistent criers’. Groups of ‘evening criers’ (N = 38) and ‘moderate cries’ (N = 55) were also selected. These 160 infants were assessed by researcher measures of their consolability and by maternal diary measures of their amounts of fussing, crying and colic behaviour when 5-6 weeks old. The persistent and evening criers cried more than the moderate criers. However, irritable, ‘fussy’ behaviour was the predominant form of distress for all three groups of infants. Colic bouts–defined as ‘bouts of intense, unsoothable crying and other behaviour, perhaps due to stomach or bowel pain’–were rare even among the persistent criers and only 7% of these infants were found to be inconsolable. The results support growing evidence that normal infant developmental processes are central to this phenomenon. In addition, social interactions between infants and parents, and parental subjective variables, appear to be involved. Colic was distinguished as a rare and separate form of distress by the infants' mothers. Further evidence needs to determine whether colic is a distinct clinical phenomenon or an extreme degree of normal distress interpreted within a western cultural framework.     

Development of infant crying behavior: A longitudinal case study

This study documents the development of infant crying behavior during the second half of the first year (across a key developmental transition). Two female infants were observed twice a month for 6 months when the infants were between 7 and 14 months of age. The infants exhibited crying behavior that seemed to become more sophisticated with increasing age. This marked a proactive stance in communicating with the mother on the part of the infant. Interestingly, at 11–12 months, “fake crying” was observed during a naturalistic interaction with the mother. This implied that deceptive infant behavior could be seen at quite an early stage.     

Maternal regulation of infant reactivity from 2 to 6 months

Previous research has investigated the effect of maternal soothing behaviors on reducing infant reactivity but not the differential effects of specific maternal behaviors on infant stress responses. The present study investigated maternal regulation of 2- and 6-month-olds' responses to an inoculation and found a significant decline with age in both the intensity and duration of infants' crying. Maternal affection and touching decreased from 2 to 6 months, whereas maternal vocalizing and distraction behaviors increased. At both ages, the combination of maternal holding/rocking and vocalizing was associated with decreases in all levels of infant reactivity. Neither strategy alone, however, was found to be effective. Feeding/ pacifying behaviors were effective only when initial distress was at a low or moderate level, which suggests that the effectiveness of maternal regulatory behaviors may depend on the intensity of infants' crying.     

Maternal experience of their infants’ crying in the context of war trauma: Determinants and consequences

We examined, first, how prenatal maternal mental health and war trauma predicted mothers’ experience of their infant crying, indicated by emotions, cognitions, and behavior; and second, how these experiences influenced the mother–infant interaction and infant development. Participants were 511 Palestinian mothers from the Gaza Strip, reporting their war trauma, symptoms of posttraumatic stress disorder (PTSD), depression, and perceived stress during pregnancy (Time 1). They reported experiences of infant crying at 4 months (Time 2), and the mother–infant interaction and infant sensorimotor and language development at 12 months of infants’ age (Time 3). Results revealed that maternal mental health problems, but not war trauma, were important to experiences of infant crying. A high level of PTSD symptoms predicted negative emotions evoked by infant crying, and high depressive symptoms predicted low active and positive responses to crying. Unexpectedly, high prenatal perceived stress predicted high active and positive responsiveness. Concerning the consequences, mothers’ sensitive interpretation of infant crying predicted optimal infant sensorimotor development, and mothers’ active and positive responses predicted high emotional availability in mother–infant interaction. Crying is the first communication tool for infants, and mothers’ sensitive responses to crying contribute to infant well-being. Therefore, reinforcing mother's optimal responses is important when helping war-affected dyads.     

Persistent crying and parenting: Search for a butterfly in a dynamic system

The risks and causes of persistent crying in early infancy are discussed on the basis of a study of 61 infants referred to the Munich Interdisciplinary Research and Intervention Program for Fussy Babies for persistent crying between 1 and 6 months of age, and of a community sample of 51 infants of the same age. Particular attention was paid to pre-verbal parent-infant communication, the development of which was interpreted in terms of a dynamic interactional system including both regulatory and communicative predispositions in infants and intuitive competence for supporting infant predispositions in parents. Neither a gut problem nor any other single causal factor was identified for persistent crying in the majority of cases. In contrast, persistent crying was significantly associated with multiple biological and psychosocial risk factors for both parents and infants. Neurological immaturity, difficult temperament and sleep problems in infants, and impaired psychological conditions, limited resources and failures of intuitive competences in mothers were found to threaten the developmental process in infants and give rise to ‘vicious circles’ which were destabilizing the interactional systems. Increased attention to intuitive parental competences is recommended as one effective model for therapeutic interventions.     

Changes in cry acoustics and distress ratings while the infant is crying

Acoustics and distress ratings were examined during four minutes of naturally occurring crying from 20 healthy, 1‐month‐old infants. Two listeners made continuous judgements of infant distress during every 10‐s segment of each cry sample. Dysphonation, number of wails, and pause duration were related to distress ratings across the 4 min of crying. Means and variances of ratings and acoustics, and the predictive value of each acoustic variable to ratings, differed in the first and second halves of the samples. Differences in the pattern of results occurred for individual infants. The results highlight the importance of studying the cry as a dynamic acoustic signal that may provide unique information about an individual infant's level of distress. Copyright © 2009 John Wiley & Sons, Ltd.     

Effects of access to a stimulating object on infant behavior during tummy time

Placing infants in a prone position for "tummy time" often is recommended to ensure appropriate infant development and to combat the effects associated with infants spending extended periods of time in a supine position. However, tummy time may be associated with inappropriate infant behavior such as crying and noncompliance. We provided continuous access to a preferred stimulus to decrease negative vocalizations and to increase the duration of an infant's head being elevated during tummy time.     

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.     

Maternal and infant touching behaviours during perturbed interactions: Associations with maternal depressive symptomatology and infant crying

Touch is an important means through which mothers and infants co-regulate during periods of stress or perturbation. The present study examined the synchrony of maternal and infant touching behaviours among 41 mother-infant dyads, some of whom were deemed at-risk due to maternal depressive symptomatology. Mothers and their 4-month-old infants participated in the Still-Face (maternal emotional unavailability; SF) and Separation (maternal physical unavailability; SP) procedures. Infant crying was examined across procedures and investigated as a brief period of perturbation. Results revealed that mothers and infants displayed a positive pattern of tactile synchrony (coordinated, analogous changes in touch) during infant crying episodes. However, dyads in the high depression group displayed significantly less affectionate touch during instances of infant crying. Furthermore, more depressive symptoms were associated with less maternal and infant touch and lower rates of infant crying. This group of dyads may be less expressive via touch, be less affected by disruptions in their interactions, have impaired regulatory abilities, or simply require minimal amounts of touch to mutually regulate following social stressors and during brief perturbation periods. These findings enrich our limited knowledge about the dynamic interplay of maternal and infant touch and inform preventative intervention programs for at-risk groups.     

Changes in the affect of infants before and after episodes of crying

This study examined the affect of infants just before the onset of crying and just after crying stopped. Two infants (between 7 and 14 months old) were observed longitudinally. In total, 102 crying episodes were analyzed. The infants displayed negative affect almost always just before starting to cry and soon after crying terminated. However, there were exceptions. Positive affect was observed. These were crying behaviors that the mother identified as “fake crying” or “emergence of fake crying”. These data indicate that, although normally infant affect just before and right after crying is negative, infants also can exhibit positive affect when they show fake crying. Infants who are capable of fake crying might communicate successfully with their caregivers.