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.     

The development of the still-face effect: Mothers do matter

The Face-to-Face Still-Face paradigm (FFSF) has been used to investigate how infants react to stressful events. However, there is little developmental data on the FFSF effect, and whether it connects to a specific relationship (e.g., to a mother versus a stranger). This prospective longitudinal study aims to evaluate developmental changes in infant reaction to the FFSF presented by the mother or a stranger at 2, 4, 6, and 8 months of age (n = 39). Results show that infant negativity was expressed less in relation to a stranger, the identity effect. Results further suggest that from 6 to 8 months of age, stranger induced protest flattens out; whereas mother induced protest decreases. The results are discussed in relation to different theories regarding infant responsiveness.     

Executive attention and self-regulation in infancy

This study investigates early executive attention in infancy by studying the relations between infant sequential looking and other behaviors predictive of later self-regulation. One early marker of executive attention development is anticipatory looking, the act of looking to the location of a target prior to its appearance in that location, a process that involves endogenous control of visual orienting. Previous studies have shown that anticipatory looking is positively related to executive attention as assessed by the ability to resolve spatial conflict in 3–4-year-old children. In the current study, anticipatory looking was positively related to cautious behavioral approach in response to non-threatening novel objects in 6- and 7-month-old infants. This finding and previous findings showing the presence of error detection in infancy are consistent with the hypothesis that there is some degree of executive attention in the first year of life. Anticipatory looking was also related to the frequency of distress, to looking away from disturbing stimuli, and to some self-regulatory behaviors. These results may indicate either early attentional regulation of emotion or close relations between early developing fear and later self-regulation. Overall, the results suggest the presence of rudimentary systems of executive attention in infants and support further studies using anticipatory looking as a measure of individual differences in attention in infancy.     

Infants in group care: their interactions with professional caregivers and parents across the second year of life

Seventy children were observed during structured play with their primary professional caregivers and three peers in the child care center and with their primary caregiving parents at home at 15 and 23 months of age. The same structured play tasks were used in the two settings and the quality of the children's interactions with caregivers and parents was rated using the same 7-point scales. As expected, the quality of caregiver–child interactions significantly increased between 15 and 23 months. At 15 months, the quality of caregiver–child interactions was significantly lower than the quality of parent–child interactions, particularly with regard to caregiver supportive presence and respect for the child's autonomy. At 23 months, however, the quality of caregiver–child interactions was no longer lower and in some respects even higher than the quality of parent–child interactions. At both ages, the children expressed more negativity towards their parents than towards their professional caregivers.     

Continuity of father-rated temperament from infancy to middle childhood

Continuity of father-rated temperament in Finnish children (n = 115) aged from 6 months (the IBQ) to 5.5 years (the CBQ) was explored within the theoretical framework developed by Rothbart. Father-rated activity level, smiling and laughter and distress to limitations showed significant differential homotypic and heterotypic continuity, while soothability, duration of orienting and fear showed significant differential heterotypic continuity. On the level of latent superconstructs, father-rated positive and negative infant affectivity accounted for 5.1, 22.7 and 10.0% of the variance in childhood extraversion, effortful control and negative affectivity, respectively. Inter-parental comparisons (n = 109 family units) revealed that father-rated continuity was similar to mother-rated continuity. These findings give empirical credence to Rothbart's theory and to father-rated temperamental continuity from infancy onwards.     

Breastfeeding and the mother–infant relationship—A review

A positive effect of breastfeeding on the mother–infant relationship is often assumed in the scientific literature, but this has not been systematically reviewed. This review aims to clarify the role of breastfeeding in the mother–infant relationship, which is conceptualized as the maternal bond toward the infant and infant attachment toward the mother. Our findings indicate that theoretical mechanisms through which breastfeeding may enhance the maternal bond or infant attachment (i.e., endocrine and sensory factors involved in breastfeeding) can be found in both humans and animal models. However, the few empirical studies investigating this association have not found convincing support for a relation between breastfeeding and the quality of the mother–infant relationship. We therefore conclude that assumptions on a positive role of breastfeeding on the mother–infant relationship are not supported by empirical evidence, and recommendation of breastfeeding should solely be based on its well-documented positive effects on infant and maternal health.     

Can an agent's false belief be corrected by an appropriate communication? Psychological reasoning in 18-month-old infants

Do 18-month-olds understand that an agent's false belief can be corrected by an appropriate, though not an inappropriate, communication? In Experiment 1, infants watched a series of events involving two agents, a ball, and two containers: a box and a cup. To start, agent1 played with the ball and then hid it in the box, while agent2 looked on. Next, in agent1's absence, agent2 moved the ball from the box to the cup. When agent1 returned, agent2 told her "The ball is in the cup!" (informative-intervention condition) or "I like the cup!" (uninformative-intervention condition). During test, agent1 reached for either the box (box event) or the cup (cup event). In the informative-intervention condition, infants who saw the box event looked reliably longer than those who saw the cup event; in the uninformative-intervention condition, the reverse pattern was found. These results suggest that infants expected agent1's false belief about the ball's location to be corrected when she was told "The ball is in the cup!", but not "I like the cup!". In Experiment 2, agent2 simply pointed to the ball's new location, and infants again expected agent1's false belief to be corrected. These and control results provide additional evidence that infants in the second year of life can attribute false beliefs to agents. In addition, the results suggest that by 18 months of age infants expect agents' false beliefs to be corrected by relevant communications involving words or gestures.     

Newborns' face recognition over changes in viewpoint

The study investigated the origins of the ability to recognize faces despite rotations in depth. Four experiments are reported that tested, using the habituation technique, whether 1-to-3-day-old infants are able to recognize the invariant aspects of a face over changes in viewpoint. Newborns failed to recognize facial perceptual invariances between profile and full-face poses (Experiment 1), and profile and 3/4 poses (Experiment 3). Conversely, newborns recognized the identity of a face through full-face and 3/4 poses (Experiment 2). This result cannot be explained as a consequence of newborns' inability to discriminate between the full-face and 3/4 points of view (Experiment 4). Overall, evidence was provided that newborns are able to derive a representation of an unfamiliar face that is resilient to a certain degree of rotation in depth, from full-face to 3/4 and vice versa.     

Learning by looking: Infants' social looking behavior across the transition from crawling to walking

This study investigated how infants gather information about their environment through looking and how that changes with increases in motor skills. In Experiment 1, 9.5- and 14-month-olds participated in a 10-min free play session with both a stranger and ambiguous toys present. There was a significant developmental progression from passive to active social engagement, as evidenced by younger infants watching others communicate more and older infants making more bids for social interaction. Experiment 2 examined longitudinally the impact of age and walking onset on this progression. The transition to independent walking marked significant changes in how often infants watched others communicate and made active bids for social interaction. Results suggest that infants transition from passive observers as crawlers to active participants in their social environment with the onset of walking.