Object play in Tajikistan: Infants engage with objects despite bounds on play.

Object play is a ubiquitous context for learning. Existing knowledge on infant object interaction has relied on Euro-American samples and observations confined to laboratory playrooms or families' homes, where object play is typically observed indoors and in rooms brimming with toys. Here we examined infants' everyday object play in Tajikistan, where spaces are uniquely laid out and homes are not child-centered and toy-abundant. The restrictive gahvora cradling practice in Tajikistan may indirectly shape how infants access and engage with objects. We documented how much time infants spent in object play, the types and diversity of objects they contacted, and the locations of play-indoors or outside. We observed 59 infants (12-24 months) during a 45-min naturalistic observation when infants were out of the gahvora. Infants engaged with objects 50% of the time. Despite a lack of object diversity, object interactions were frequent and dispersed throughout observations. Walkers tended to divide their object interactions between time spent indoors and outside, but pre-walkers mostly interacted with objects indoors. Caregivers inadvertently shape infants' opportunities for exploration and play through culturally guided childrearing practices. And infants make due: they take it upon themselves to move, explore, and engage-gleaning culturally relevant routines.

Gahvora cradling in Tajikistan: Cultural practices and associations with motor development.

In Tajikistan, infants are bound supine in a "gahvora" cradle that severely restricts movement. Does cradling affect motor development and body growth? In three studies (2013-2018), we investigated associations between time in the gahvora (within days and across age) and motor skills and flattened head dimensions in 8-24-month-old Tajik infants (N = 269, 133 girls, 136 boys)) and 4.3-5.1-year-old children (N = 91, 53 girls, 38 boys). Infants had later motor onset ages relative to World Health Organization standards and pronounced brachycephaly; cradling predicted walk onset age and the proficiency of sitting, crawling, and walking. By 4-5 years, children's motor skills were comparable with US norms. Cultural differences in early experiences offer a unique lens onto developmental processes and equifinality in development.

Diversity and representation in infant research: Barriers and bridges toward a globalized science of infant development.

Psychological researchers have become increasingly concerned with generalized accounts of human behavior based on narrow participant representation. This concern is particularly germane to infant research as findings from infant studies are often invoked to theorize broadly about the origins of human behavior. In this article, we examined participant diversity and representation in research published on infant development in four journals over the past decade. Sociodemographic data were coded for all articles reporting infant data published in Child Development, Developmental Science, Developmental Psychology, and Infancy between 2011 and 2022. Analyses of 1682 empirical articles, sampling approximately 1 million participants, revealed consistent under-reporting of sociodemographic information. For studies that reported sociodemographic characteristics, there was an unwavering skew toward White infants from North America/Western Europe. To address a lack of diversity in infant studies and its scientific impact, a set of principles and practices are proposed to advance toward a more globally representative science.

Comparison of U.S. and Tajik infants' time in containment devices.

How infants are held or contained throughout the day shape infants' experiences, particularly around movement and exploration. In Tajikistan, caregivers use "gahvora" cradles, which severely restrict the body and limbs. The present study explored the variability and use of containment devices in U.S. and Tajik infants. Using time diaries, we compared 12-month-olds in the U.S. and Tajikistan on the types of containments used and time spent in them throughout the day. During the day, Tajik infants accumulated more time in gahvoras than infants in the U.S. spent in cribs, primarily used for sleep, suggesting gahvoras served other functions. Given the availability of other devices, U.S. infants' time was distributed in short yet frequent bouts across devices. Accumulated time in these containments matched accumulated time Tajik infants spent in gahvoras. Tajik infants accumulated more unrestricted time on the ground, which was distributed in prolonged bouts, than U.S. infants. Findings highlight differences in infants' everyday experiences during the developmental period when motor skills emerge. By embracing commonalities and exploring differences between cultures, this study offers insights into differences in infants' everyday experiences and opportunities for movement.

Places and postures: A cross-cultural comparison of sitting in 5-month-olds.

Motor development-traditionally described in terms of age-related stages-is typically studied in the laboratory with participants of Western European descent. Cross-cultural studies typically focus on group differences in age-related stages relative to Western norms. We adopted a less traditional approach: We observed 5-month-olds and their mothers from six cultural groups around the world during one hour at home while they engaged in natural daily activities. We examined group differences in infants' sitting proficiency, everyday opportunities to practice sitting, the surfaces on which sitting took place, and mothers' proximity to sitting infants. Infants had opportunities to practice sitting in varied contexts-including ground, infant chairs, and raised surfaces. Proficiency varied considerably within and between cultural groups: 64% of the sample sat only with support from mother or furniture and 36% sat independently. Some infants sat unsupported for 20+ minutes, in some cases so securely that mothers moved beyond arms' reach of their infants even while infants sat on raised surfaces. Our observations of infant sitting across cultures provide new insights into the striking range of ability, varied opportunities for practice, and contextual factors that influence the proficiency of infant motor skills.

Crawling and walking infants elicit different verbal responses from mothers.

We examined mothers' verbal responses to their crawling or walking infants' object sharing (i.e. bids). Fifty mothers and their 13-month-olds were observed for 1 hour at home. Infants bid from a stationary position or they bid after carrying the object to their mothers. Mothers responded with affirmations (e.g. 'thank you'), descriptions ('red box'), or action directives ('open it'). Infants' locomotor status and the form of their bids predicted how mothers responded. Mothers of walkers responded with action directives more often than mothers of crawlers. Notably, differences in the responses of mothers of walkers versus those of crawlers were explained by differences in bid form between the two groups of infants. Walkers were more likely to engage in moving bids than crawlers, who typically shared objects from stationary positions. When crawlers displayed moving bids, their mothers offered action directives just as often as did mothers of walkers. Findings illustrate developmental cascades, wherein Infants' locomotor status affects how infants share objects with mothers, which in turn shapes mothers' verbal responses.

Natural-ish behavior: The interplay of culture and context in shaping motor behavior in infancy.

What is natural behavior and how does it differ from laboratory-based behavior? The "natural" in natural behavior implies the everyday, complex, ever-changing, yet predictable environment in which children grow up. "Behavior" is motor action and is foundational to psychology, as it includes all things to function in everyday environments. Is behavior demonstrated in the laboratory un-natural? Suppose behavior emerges spontaneously, in a context that is most common to the animal but an observer is there to document it using particular research tools. Is that behavior natural or natural-ish? Methods can powerfully affect conclusions about infant experiences and learning. In the lab, tasks are typically narrowly constrained where infants and children have little opportunity to display the variety of behaviors in their repertoire. Data from naturalistic observations may paint a very different picture of learning and development from those based on structured tasks, exposing striking variability in the environment and behavior and new relations between the organism and its environment. Using motor development as a model system, in this chapter we compare frameworks, methods, and findings originating in the lab and in the field, applied and adapted in different settings. Specifically, we recount our journey of pursuing the study of cultural influences on motor development in Tajikistan, and the challenges, surprises, and lessons learned.

Social dynamics of supported walking in 11-month-old infants.

Before infants walk independently, they move upright with support by holding caregivers' hands, pushing a wheeled walker, and "cruising" along walls or furniture. To what extent do caregivers and infants engage in these activities and do these experiences with supported walking relate to independent walking status? To address these questions, we assessed supported walking in 50 11-month-olds and their mothers in the context of everyday routines. For each bout of supported walking, coders scored the type of support, frequency of supported bouts, and the number of steps infants took per bout. Mothers tracked onset ages for independent walking prospectively, and researchers verified infants' walking skill using a standardized task. Infants who produced more child-controlled supported walking achieved independent walking earlier than infants who produced less child-controlled supported walking. But, supported walking experience did not predict proficiency of independent walking, suggesting that the two types of locomotion are distinct. These data highlight the role of experience of locomotor behaviors and indicate that not all experience is equally effective.

Real-time teaching and learning: Caregivers teaching infants to descend stairs.

Learning to descend stairs requires motor and cognitive capacities on the part of infants and opportunities for practice and assurance of safety offered by caregivers. The American Academy of Pediatrics prescribes the age strategy to teach toddlers to safely descend stairs but without much consideration for individual differences in infants' skills or caregivers' techniques. The purpose of this study was to observe the natural ways in which caregivers teach infants to descend stairs at home and the extent to which infants abide. Of particular interest was to examine the dynamic nature of caregivers' teaching and infants' learning over the session with attention to individual differences. Dyads (N = 59) were videorecorded on Zoom for 10 min interacting on stairs at home in the United States, Brazil, Canada, Italy, and Spain. Infants (n = 30 girls, 29 boys; 13-month-olds ± 1 week) were novice walkers (M = 2.04 months walking experience). Caregivers used a variety of teaching strategies and focused on "backing" and "scooting." Infants were more likely to heed caregivers' guidance when caregivers provided hands-on support and verbal encouragement suggesting infants were engaged and responsive to caregivers' overtures. Infants' walking experience predicted change in descent strategy over the session. Although infants did not show evidence of learning over the session, consistent caregiver instruction suggested caregivers were persistent, if not effective, teachers. Teaching and learning motor skills in a potentially risky task creates a unique opportunity for interaction, allowing infants and caregivers to learn from one another. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Transition from crawling to walking and infants' actions with objects and people.

Associations between infants' transition to walking and object activities were examined. Fifty infants were observed longitudinally during home observations. At 11 months, all infants were crawlers; at 13 months, half became walkers. Over age, infants increased their total time with objects and frequency of sharing objects with mothers. Bidirectional influences between locomotion and object actions were found. Walking was associated with new forms of object behaviors: Walkers accessed distant objects, carried objects, and approached mothers to share objects; crawlers preferred objects close at hand and shared objects while remaining stationary. Earlier object activities predicted walking status: Crawlers who accessed distant objects, carried objects, and shared objects over distances at 11 months were more likely to walk by 13 months.

WEIRD walking: cross-cultural research on motor development.

Motor development - traditionally studied in WEIRD populations - falls victim to assumptions of universality similar to other domains described by Henrich et al. However, cross-cultural research illustrates the extraordinary diversity that is normal in motor skill acquisition. Indeed, motor development provides an important domain for evaluating cultural challenges to a general behavioral science.

Learning the designed actions of everyday objects.

How do young children learn to use everyday artifacts-doorknobs, zippers, and so on-in the ways they were designed to be used? Although the designed actions of such objects seem obvious to adults, little is known about how young children learn the "hidden affordances" of everyday objects. We encouraged 115 11- to 37-month-old children to open 2 types of containers: circular jars with twist-off lids (Experiment 1) and rectangular Tupperware-style containers with pull-off lids (Experiment 2). We varied container size to examine effects of the body-environment fit on display of the designed action and successful implementation of the designed action. Results showed a developmental progression from nondesigned actions to performance of the designed twisting or pulling actions to successful implementation of the designed action. Nondesigned actions decreased with age as performance of the designed action increased. Successful implementation lagged behind performance of the designed action. That is, even after children appeared to know what to do, they were still unsuccessful in opening the container. Why? For twist-offs, very large lids were difficult to manipulate, and younger children often twisted to the right, or in both directions, and did not persist in consecutive turns to the left. Larger pull-off containers required new strategies to stabilize the base, such as holding the container against the tabletop or the chest. Findings provide insights into the body-environment factors that facilitate children's learning and implementation of the hidden affordances inherent in everyday artifacts. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

When infants take mothers' advice: 18-month-olds integrate perceptual and social information to guide motor action.

The social cognition and perception-action literatures are largely separate, both conceptually and empirically. However, both areas of research emphasize infants' emerging abilities to use available information--social and perceptual information, respectively--for making decisions about action. Borrowing methods from both research traditions, this study examined whether 18-month-old infants incorporate both social and perceptual information in their motor decisions. The infants' task was to determine whether to walk down slopes of varying risk levels as their mothers encouraged or discouraged walking. First, a psychophysical procedure was used to determine slopes that were safe, borderline, and risky for individual infants. Next, during a series of test trials, infants received mothers' advice about whether to walk. Infants used social information selectively: They ignored encouraging advice to walk down risky slopes and discouraging advice to avoid safe slopes, but they deferred to mothers' advice at borderline slopes. Findings indicate that 18-month-old infants correctly weigh competing sources of information when making decisions about motor action and that they rely on social information only when perceptual information is inadequate or uncertain.

Locomotor experience and use of social information are posture specific.

The authors examined the effects of locomotor experience on infants' perceptual judgments in a potentially risky situation--descending steep and shallow slopes--while manipulating social incentives to determine where perceptual judgments are most malleable. Twelve-month-old experienced crawlers and novice walkers were tested on an adjustable sloping walkway as their mothers encouraged and discouraged descent. A psychophysical procedure was used to estimate infants' ability to crawl/walk down slopes, followed by test trials in which mothers encouraged and discouraged infants to crawl/walk down. Both locomotor experience and social incentives affected perceptual judgments. In the encourage condition, crawlers only attempted safe slopes within their abilities, but walkers repeatedly attempted impossibly risky slopes, replicating previous work. The discourage condition showed where judgments are most malleable. When mothers provided negative social incentives, crawlers occasionally avoided safe slopes, and walkers occasionally avoided the most extreme 50 degrees increment, although they attempted to walk on more than half the trials. Findings indicate that both locomotor experience and social incentives play key roles in adaptive responding, but the benefits are specific to the posture that infants use for balance and locomotion.

The ties that bind: Cradling in Tajikistan.

A traditional childrearing practice-"gahvora" cradling-in Tajikistan and other parts of Central Asia purportedly restricts movement of infants' body and limbs. However, the practice has been documented only informally in anecdotal reports. Thus, this study had two research questions: (1) To what extent are infants' movements restricted in the gahvora? (2) How is time in the gahvora distributed over a 24-hour day in infants from 1-24 months of age? To answer these questions, we video-recorded 146 mothers cradling their infants and interviewed them using 24-hour time diaries to determine the distribution of time infants spent in the gahvora within a day and across age. Infants' movements were indeed severely restricted. Although mothers showed striking uniformity in how they restricted infants' movements, they showed large individual differences in amount and distribution of daily use. Machine learning algorithms yielded three patterns of use: day and nighttime cradling, mostly nighttime cradling, and mostly daytime cradling, suggesting multiple functions of the cradling practice. Across age, time in the gahvora decreased, yet 20% of 12- to 24-month-olds spent more than 15 hours bound in the gahvora. We discuss the challenges and benefits of cultural research, and how the discovery of new phenomena may defy Western assumptions about childrearing and development. Future work will determine whether the extent and timing of restriction impacts infants' physical and psychological development.

Decisions at the Brink: Locomotor Experience Affects Infants' Use of Social Information on an Adjustable Drop-off.

How do infants decide what to do at the brink of a precipice? Infants could use two sources of information to guide their actions: perceptual information generated by their own exploratory activity and social information offered by their caregivers. The current study investigated the role of locomotor experience in using social information-both encouragement and discouragement-for descending drop-offs. Mothers of 30 infants (experienced 12-month-old crawlers, novice 12-month-old walkers, and experienced 18-month-old walkers) encouraged and discouraged descent on a gradation of drop-offs (safe "steps" and risky "cliffs"). Novice walkers descended more frequently than experienced crawlers and walkers and fell while attempting to walk over impossibly high cliffs. All infants showed evidence of integrating perceptual and social information, but locomotor experience affected infants' use of social messages, especially on risky drop-offs. Experienced crawlers and walkers selectively deferred to social information when perceptual information is ambiguous. In contrast, novice walkers took mothers' advice inconsistently and only at extreme drop-offs.

Carry on: spontaneous object carrying in 13-month-old crawling and walking infants.

Carrying objects requires coordination of manual action and locomotion. This study investigated spontaneous carrying in 24 walkers who were 13 months old and 26 crawlers who were 13 months old during 1-hr, naturalistic observations in the infants' homes. Carrying was more common in walkers, but crawlers also carried objects. Typically, walkers carried objects in their hands, whereas crawlers multitasked by using their hands simultaneously for holding objects and supporting their bodies. Locomotor experience predicted frequency of carrying in both groups, suggesting that experienced crawlers and walkers perceive their increased abilities to handle objects while in motion. Despite additional biomechanical constraints imposed by holding an object, carrying may actually improve upright balance: Crawlers rarely fell while carrying an object, and walkers were more likely to fall without an object in hand than while carrying. Thus, without incurring an additional risk of falling, spontaneous carrying may provide infants with new avenues for combining locomotor and manual skills and for interacting with their environments.

Using social information to guide action: infants' locomotion over slippery slopes.

In uncertain situations such as descending challenging slopes, social signals from caregivers can provide infants with important information for guiding action. Previous work showed that 18-month-old walking infants use social information selectively, only when risk of falling is uncertain. Experiment 1 was designed to alter infants' region of uncertainty for walking down slopes. Slippery Teflon-soled shoes drastically impaired 18-month-olds' ability to walk down slopes compared with walking barefoot or in standard crepe-soled shoes, shifting the region of uncertainty to a shallower range of slopes. In Experiment 2, infants wore Teflon-soled shoes while walking down slopes as their mothers encouraged and discouraged them from walking. Infants relied on social information on shallow slopes, even at 0°, where the probability of walking successfully was uncertain in the Teflon-soled shoes. Findings indicate that infants' use of social information is dynamically attuned to situational factors and the state of their current abilities.