Caregiver encouragement to act on objects is related with crawling infants' receptive language

The progression from crawling to walking in infancy is associated with changes in infant language development. One possible explanation for such change is the infant's language environment. Prior research indicates that caregivers use more action directives with walking infants compared to crawling infants, but the relations of such parental speech with infant vocabulary is unknown. Here, we present findings from day-long home audio recordings (Study 1) and laboratory observations (Study 2) of same-aged crawling and walking infants to explore how caregiver language, specifically action directives, were associated with parent reported infant vocabulary size. Findings in both studies indicated that caregiver action directives were associated with crawling, but not walking infants' receptive vocabulary sizes. Specifically, action directives about objects occurring when the infant and caregiver were not jointly engaged were associated with higher receptive vocabulary scores for crawling infants, but no such pattern was found for walking infants. The replication of results in distinct samples with different research methodologies strengthens the findings. Taken together, these studies demonstrate that caregiver social engagement specific to infant motoric development is related with infant language learning.

Studying hot executive function in infancy: Insights from research on emotional development

Recent calls have urged to bridge the fields of emotional and cognitive development to advance theoretical and empirical pursuits. Yet, despite notable overlap between research on executive function and emotion regulation, a uniting theory that informs future avenues of research is lacking. Infants are known to lack emotion regulation skills, as they are developing the abilities to regulate their emotions and coordinated responses. However, the field of emotional development demonstrates that at an early age, infants are adept at regulating their behaviors in response to others emotional reactions. Moreover, although classic delay of gratification tasks are fairly ecological measures, rarely are rules expressed to infants without emotions. This paper draws from recent interest in hot executive function to link infancy research on executive function and emotion. Hot executive function lends itself as a useful construct in this endeavor because it unites the study emotion and executive function. We offer a perspective that refines hot executive function within prominent emotion theories while discussing infant executive function and emotion empirical pursuits. Our perspective presents reliable paradigms from the field of emotional development to serve as tools for studying the development of hot executive function.

Infants use emotion to infer intentionality from non-random sampling events

Infants use statistical information in their environment, as well as others' emotional communication, to understand the intentions of social partners. However, rarely do researchers consider these two sources of social information in tandem. This study assessed 2-year-olds' attributions of intentionality from non-random sampling events and subsequent discrete emotion reactions. Infants observed an experimenter remove five objects from either the non-random minority (18%) or random majority (82%) of a sample and express either joy, disgust, or sadness after each selection. Two-year-olds inferred the experimenter's intentionality by giving her the object that she had previously selected when she expressed joy or disgust after non-random sampling events, but not when she expressed sadness or sampled at random. These findings demonstrate that infants use both statistical regularities and discrete emotion communication to infer an agent's intentions. In particular, the present findings show that 2-year-olds infer that an agent can intentionally select a preferred or an undesired object from a sample as a function of the discrete emotion. Implications for the development of inferring intentionality from statistical sampling events and discrete emotion communication are discussed.

Adult responses to infant prelinguistic vocalizations are associated with infant vocabulary: A home observation study

This study used LENA recording devices to capture infants' home language environments and examine how qualitative differences in adult responding to infant vocalizations related to infant vocabulary. Infant-directed speech and infant vocalizations were coded in samples taken from daylong home audio recordings of 13-month-old infants. Infant speech-related vocalizations were identified and coded as either canonical or non-canonical. Infant-directed adult speech was identified and classified into different pragmatic types. Multiple regressions examined the relation between adult responsiveness, imitating, recasting, and expanding and infant canonical and non-canonical vocalizations with caregiver-reported infant receptive and productive vocabulary. An interaction between adult like-sound responding (i.e., the total number of imitations, recasts, and expansions) and infant canonical vocalizations indicated that infants who produced more canonical vocalizations and received more adult like-sound responses had higher productive vocabularies. When sequences were analyzed, infant canonical vocalizations that preceded and followed adult recasts and expansions were positively associated with infant productive vocabulary. These findings provide insights into how infant-adult vocal exchanges are related to early vocabulary development.

Morality is relative: Anger, disgust, and aggression as contingent responses to sibling versus acquaintance harm

Angry reactions to moral violations should be heightened when wrongs befall oneself in comparison with when wrongs befall acquaintances, as prior research by Molho, Tybur, Güler, Balliet, and Hofmann (2017) demonstrates, because aggressive confrontation is inherently risky and therefore only incentivized by natural selection to curtail significant fitness costs. Here, in 3 preregistered studies, we extend this sociofunctional perspective to cases of wrongs inflicted on siblings. We observed equivalently heightened anger in response to transgressions against either oneself or one's sibling relative to transgressions against acquaintances across studies, whereas transgressions against acquaintances evoked greater disgust and/or fear (both associated with social avoidance) in 2 of the 3 studies. Studies 2 and 3, which incorporated measures of tendencies to confront the transgressor, confirmed that the elevated anger elicited by self or sibling harm partially mediated heightened inclinations toward direct aggression. Finally, in Study 3 we compared tendencies to experience anger and to directly aggress on behalf of siblings and close friends. Despite reporting greater affiliative closeness for friends than for siblings, harm to friends failed to evoke heightened anger relative to acquaintance harm, and participants were inclined to directly aggress against those who had harmed their sibling to a significantly greater extent than when the harm befell their friend. These overall results broadly replicate Molho et al.'s (2017) findings and theoretically extend the sociofunctionalist account of moral emotions to kinship. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

The influence of context on distinct facial expressions of disgust

Face perception is susceptible to contextual influence and perceived physical similarities between emotion cues. However, studies often use structurally homogeneous facial expressions, making it difficult to explore how within-emotion variability in facial configuration affects emotion perception. This study examined the influence of context on the emotional perception of categorically identical, yet physically distinct, facial expressions of disgust. Participants categorized two perceptually distinct disgust facial expressions, "closed" (i.e., scrunched nose, closed mouth) and "open" (i.e., scrunched nose, open mouth, protruding tongue), that were embedded in contexts comprising emotion postures and scenes. Results demonstrated that the effect of nonfacial elements was significantly stronger for "open" disgust facial expressions than "closed" disgust facial expressions. These findings provide support that physical similarity within discrete categories of facial expressions is mutable and plays an important role in affective face perception. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Putting "context" in context: The effects of body posture and emotion scene on adult categorizations of disgust facial expressions

Affective face perception is influenced by nonfacial contextual elements. However, investigations often conflate body posture and emotion scene, making it unclear whether posture or the combination of posture and scene produces perception-altering effects. This study examined adults' categorizations of disgust facial expressions superimposed onto isolated emotion postures or postures embedded in emotion scenes. Results indicated that emotional postures exerted a significant contextual effect on adults' emotion categorizations of disgust faces. Of note, postures in emotion scenes exerted a stronger contextual effect than isolated postures for sadness and fear contexts. These findings suggest that contextual elements exert varying degrees of influence on emotion perception and produce combinatorial effects. (PsycINFO Database Record

Postural Communication of Emotion: Perception of Distinct Poses of Five Discrete Emotions

Emotion can be communicated through multiple distinct modalities. However, an often-ignored channel of communication is posture. Recent research indicates that bodily posture plays an important role in the perception of emotion. However, research examining postural communication of emotion is limited by the variety of validated emotion poses and unknown cohesion of categorical and dimensional ratings. The present study addressed these limitations. Specifically, we examined individuals' (1) categorization of emotion postures depicting 5 discrete emotions (joy, sadness, fear, anger, and disgust), (2) categorization of different poses depicting the same discrete emotion, and (3) ratings of valence and arousal for each emotion pose. Findings revealed that participants successfully categorized each posture as the target emotion, including disgust. Moreover, participants accurately identified multiple distinct poses within each emotion category. In addition to the categorical responses, dimensional ratings of valence and arousal revealed interesting overlap and distinctions between and within emotion categories. These findings provide the first evidence of an identifiable posture for disgust and instantiate the principle of equifinality of emotional communication through the inclusion of distinct poses within emotion categories. Additionally, the dimensional ratings corroborated the categorical data and provide further granularity for future researchers to consider in examining how distinct emotion poses are perceived.

A recurring salmonellosis epidemic in New Zealand linked to contact with sheep

One strain of Salmonella Brandenburg began causing large numbers of human infections in New Zealand in 1998. We investigated the emergence of this strain using combined notification and laboratory data on human and animal disease and a case-control study. S. Brandenburg infection in humans was characterized by spring peaks and high rates in the southern half of the South Island. This epidemic pattern followed very closely that seen in sheep. The case-control study found that infection was significantly associated with occupational contact with sheep and having a household member who had occupational contact with sheep, during the 3 days prior to illness or interview. We conclude that S. Brandenburg has become established as a zoonotic disease in New Zealand. Preventing infection requires control of the epidemic in sheep through vaccination, changes in farm management practices, and promotion of hand washing and other precautions to protect farmers and their families.

Continuing Mycobacterium bovis transmission from animals to humans in New Zealand

New Zealand has a large reservoir of Mycobacterium bovis infection in wild and farmed animals. This study aimed to assess the extent of human infection with this organism and the potential contribution of these animal sources. Combined epidemiological and laboratory investigation of human tuberculosis cases over the period 1995-2002 showed that M. bovis accounted for 2.7% (54/1997) of laboratory-confirmed human tuberculosis cases, a rate of 0.2/100,000 population. M. bovis isolates from humans (23) were typed using restriction endonuclease analysis (REA) and compared with isolates from wild and domestic animals (2600). Fourteen (61%) of the human isolates had REA patterns that were identical to patterns for isolates from cattle, deer, possums, ferrets, pigs, and occasionally cats. These results suggest a low level of ongoing M. bovis transmission from animal reservoirs to humans in New Zealand.