Similar Developmental Trajectory Research Articles

A common trajectory of gut microbiome development during the first month in healthy neonates with limited inter-individual environmental variations

The early development of the gut microbiome is governed by multiple factors and has significantly long-term effects on later-in-life health. To minimize inter-individual variations in the environment, we determined developmental trajectories of the gut microbiome in 28 healthy neonates during their stay at a postpartum center. Stool samples were collected at three time points: the first-pass meconium within 24 h of life, and at 7 and 28 days of age. Illumina sequencing of the V3–V4 region of 16S rRNA was used to investigate microbiota profiles. We found that there was a distinct microbiota structure at each time point, with a significant shift during the first week. Proteobacteria was most abundant in the first-pass meconium; Firmicutes and Actinobacteria increased with age and were substituted as the major components. Except for a short-term influence of different delivery modes on the microbiota composition, early microbiome development was not remarkably affected by gravidity, maternal intrapartum antibiotic treatment, premature rupture of membranes, or postnatal phototherapy. Hence, our data showed a similar developmental trajectory of the gut microbiome during the first month in healthy neonates when limited in environmental variations. Environmental factors external to the host were crucial in the early microbiome development.

Preschool Mandarin-speaking children’s comprehension of associative anaphora

Associative anaphora refers to a discourse operation that links a definite determiner phrase (DP) to an antecedent that acts as an indirect referent of the definite DP. For example, in the sequence ‘I bought a laptop. The keyboard was black’, the definite DP ‘the keyboard’ is linked to ‘a laptop’, meaning ‘the keyboard of the laptop’. The development of children’s knowledge of associative anaphora has long been investigated in child language research, as it provides a unique window into the interaction between linguistic and nonlinguistic cognitive abilities. However, most prior research focused on Indo-European languages without looking at typologically distinct languages. To fill the gap, this study investigated children’s knowledge of associative anaphora in Mandarin Chinese, a typologically distinct language, thus allowing for a better cross-linguistic understanding of the phenomenon. Ninety-one 3- to 5-year-olds were investigated using a truth-value judgment task. The findings were that Mandarin-speaking children exhibited a similar developmental trajectory and were impacted by the same cognitive factors as observed in children speaking Indo-European languages. The implications of the findings were then discussed in relation to the role of processing factors and language-specific properties.

Infants’ representations of the infant body in the first year of life: a preferential looking time study

Representing others’ bodies is of fundamental importance for interacting with our environment, yet little is known about how body representations develop. Previous research suggests that infants have expectations about the typical structure of human bodies from relatively early in life, but that these expectations are dependent on how closely the stimuli resemble the bodies infants are exposed to in daily life. Yet, all previous studies used images of adult human bodies, and therefore it is unknown whether infants’ representations of infant bodies follow a similar developmental trajectory. In this study we investigated whether infants have expectations about the relative size of infant body parts in a preferential looking study using typical and disproportional infant bodies. We recorded the looking behaviour of three groups of infants between 5 and 14 months of age while they watched images of upright and inverted infant bodies, typical and proportionally distorted, and also collected data on participants’ locomotor abilities. Our results showed that infants of all ages looked equally at the typical and proportionally distorted infant body stimuli in both the upright and inverted conditions, and that their looking behaviour was unrelated to their locomotor skills. These findings suggest that infants may need additional visual experience with infant bodies to develop expectations about their typical proportions.

Article comprehension in monolingual Spanish-speaking children with developmental language disorder: A longitudinal eye tracking study

Purpose Article-noun disagreement in spoken language is a marker of children with developmental language disorder (DLD). However, the evidence is less clear regarding article comprehension. This study investigates article comprehension in monolingual Spanish-speaking children with and without DLD. Method Eye tracking methodology used in a longitudinal experimental design enabled the examination of real time article comprehension. The children at the time 1 were 40 monolingual Spanish-speaking preschoolers (20 with DLD and 20 with typical language development [TLD]). A year later (time 2), 27 of these children (15 with DLD and 12 with TLD) were evaluated. Children listened to simple phrases while inspecting a four object visual context. The article in the phrase agreed in number and gender with only one of the objects. Result At the time 1, children with DLD did not use articles to identify the correct image, while children with TLD anticipated the correct picture. At the time 2, both groups used the articles’ morphological markers, but children with DLD showed a slower and weaker preference for the correct referent compared to their age-matched peers. Conclusion These findings suggest a later emergence, but a similar developmental trajectory, of article comprehension in children with DLD compared to their peers with TLD.

Intelligence Education for National Security and Public Safety Policy: A Comparative Analysis of Nigeria, South Africa, and Indonesia

National security and public safet policy have become one of the important issues around the world. In some cases, the national security very close to how the State provides various instruments in maintaining national stability, including policies and laws. Nigeria, South Africa, and Indonesia are facing various challenges of national stability including various national security threats. For Nigeria, post-colonial hangs over and extended militarism created huge challenges for the democratisation of intelligence education and training, while in South Africa, centuries of repressive apartheid regime created institutional obstacles for a virile democratic intelligence education and training. This work therefore is a comparative analysis of intelligence education and training in Africa-Nigeria, South Africa, and Indonesia. Using a historiographic and content evaluative methods, the study was able to establish similar developmental trajectory of intelligence education and training in Nigeria, South Africa, and Indonesia and recommended the urgent need for extensive collaboration between the countries to develop a model of intelligence education and training to attenuate the pervasive national security and public safety threats challenges in the countries.

A Developmental Study of Mirror-Gazing-Induced Anomalous Self-Experiences and Self-Reported Schizotypy from 7 to 28 Years of Age

Introduction: The mirror-gazing task (MGT) is an experimental paradigm inducing anomalous perceptions and anomalous experiences of self-face (ASEs) in the general population, ranging from changes in light and color, to face deformation, to experiencing one’s specular image as another identity. Subclinical ASEs have been related to the emergence of the risk for developing psychotic disorders, and inducing such states in the general population could shed light on the factors underlying interindividual differences in proneness to these phenomena. We aimed to examine the influence of schizotypal personality traits on proneness to experiencing induced ASEs from a developmental perspective, from childhood to adulthood. Methods: Two hundred and sixteen children, adolescents, and young adults participated in the MGT, and their schizotypal personality traits were assessed with the Schizotypal Personality Questionnaire. Statistical analyses assessed the relationship between schizotypy dimensions and induced ASEs, and we further tested their dynamic relationship as function of age (from childhood to adulthood). Results: Results confirmed the developmental trajectory of the different schizotypy dimensions, with scores peaking during adolescence, and proneness to induced ASEs seemed to follow a similar developmental trajectory. Moreover, positive (p = 0.001) and disorganized (p = 0.004) dimensions were found to contribute to the proneness to experiencing induced ASEs. Finally, the developmental model showed that positive schizotypy (p = 0.035) uniquely distinguished between experiencing other-identity phenomena between childhood and adulthood. Conclusion: This study has the potential to inform research on early detection of psychosis through a developmental approach and links the concept of schizotypy with processes of perceptual self-distortions.

CD-1 Outbred Mice Produce Less Variable Ultrasonic Vocalizations Than FVB Inbred Mice, While Displaying a Similar Developmental Trajectory.

The production of ultrasonic vocalizations (USVs) in neonatal mice is a critical means of communication that is used to elicit maternal care. Alterations in neonatal USV production is also an indicator of neurological deficits. However, USVs have been predominately assessed in inbred animals and are significantly understudied in outbred mice, even though outbred animals better represent the genetic diversity of humans and are used in several neurological disorder models. To determine the reproducibility of USVs across models, we compared male and female CD-1 (outbred) and FVB (inbred) mice on postnatal days (PD) 4, 8, 12, 16, and 20. We found that CD-1 and FVB mice displayed a similar developmental trajectory of USVs. However, CD1 mice emitted more USVs on PD 12 than FVB mice. In addition, FVB mice emitted a longer duration of calls on PD 4 and 8 and a higher overall maximum and minimum frequency of USVs than CD-1 mice. No differences in mean amplitude were found between groups. We also detected numerous significant differences between outbred and inbred mice when comparing each group's call composition. We next assessed the relative variability of mouse vocalizations between groups, finding that outbred mice were less variable than inbred mice. For the spectral and temporal characteristics of the USVs, variability was similar between groups. Altogether, we found that CD-1 outbred mice display a similar, if not lower, degree of variability than FVB inbred mice when assessing neonatal USVs.

A transient postnatal quiescent period precedes emergence of mature cortical dynamics.

Mature neural networks synchronize and integrate spatiotemporal activity patterns to support cognition. Emergence of these activity patterns and functions is believed to be developmentally regulated, but the postnatal time course for neural networks to perform complex computations remains unknown. We investigate the progression of large-scale synaptic and cellular activity patterns across development using high spatiotemporal resolution in vivo electrophysiology in immature mice. We reveal that mature cortical processes emerge rapidly and simultaneously after a discrete but volatile transition period at the beginning of the second postnatal week of rodent development. The transition is characterized by relative neural quiescence, after which spatially distributed, temporally precise, and internally organized activity occurs. We demonstrate a similar developmental trajectory in humans, suggesting an evolutionarily conserved mechanism that could facilitate a transition in network operation. We hypothesize that this transient quiescent period is a requisite for the subsequent emergence of coordinated cortical networks.

Reproducibility and validity of the Functional Communication Classification System for young children with cerebral palsy.

To examine interrater agreement and validity of the Functional Communication Classification System (FCCS) for young children with cerebral palsy (CP) aged 2 or 3 years. Speech-language pathologist (SLP) and parent FCCS ratings for 31 children with CP (aged 2y, n=16; aged 3y, n=15; 18 males, 13 females) were examined for interrater agreement using a weighted Cohen's kappa statistic. Relationships between FCCS (SLP) ratings and: (1) concurrent validity with the Language Use Inventory, a standardized pragmatic assessment for children aged 18 to 47 months, (2) gross motor and fine motor function, (3) associated impairments (visual and intellectual), and (4) primary expressive communication mode were examined using Spearman's correlation coefficients. Almost perfect interrater agreement between SLP and parent FCCS ratings were found (kw =0.94). Correlations with FCCS (SLP) were excellent for pragmatic function (rs =-0.83,p<0.001), intellectual function (rs =0.89, p<0.001), and primary expressive communication mode (rs =0.92,p<0.001). Correlations were good for gross motor function (rs =0.72,p<0.001) and visual impairment (rs =0.70,p<0.001) and fair for fine motor function (rs =0.53,p<0.002). Analysis was unwarranted for epilepsy (n=1 out of 31) and hearing-associated impairments (n=0 out of 31). The FCCS has excellent interrater agreement and validity for communication classification of children with CP aged 2 or 3 years and is highly suitable for surveillance and research purposes. What this paper adds The Functional Communication Classification System (FCCS) is a valid instrument for children with cerebral palsy (CP) aged 2 or 3 years. Excellent agreement exists between speech-language pathologist and parent FCCS ratings. The FCCS has excellent correlation with intelligence, pragmatic function, and primary expressive mode. Stronger correlations with the Gross Motor Function Classification System and vision exist for children aged 2 or 3 years. Weaker correlations with manual ability exist when compared to older children with CP.

Characterization of digestive enzymes during early ontogeny of white Snook (Centropomus viridis).

The white snook (Centropomus viridis) is a species with great aquaculture potential, therefore, the present study aims two objectives; 1) to characterize digestive enzymatic activity during larval development and; 2) characterize the diversity and functionality of digestive enzymes in an early juvenile stage of C. viridis. On first feeding, larvae were 2.75 ± 0.09 mm total length and grew to 24.35 ± 4.35 mm after 42 days. The specific activity of acid proteases was detected with low activity from day 1 (Days after hatching, DAH) to day 21, and increased at 23 DAH, reaching maximum activity at 40 DAH. Meanwhile, digestive enzymatic activity of alkaline proteases was observed from hatching to day 40. From hatching until 40 DAH, the presence of alkaline proteases, trypsin, chymotrypsin, leucine aminopeptidase, α-amylase and lipase were detected with different activity patterns. Total and specific activity of digestive enzymes on juveniles showed higher activity of acid than alkaline proteases, while α-amylase had a higher activity than lipases. The maximum activity of acid proteases was observed at 40 °C and at pH 2.0, while digestive alkaline proteases showed maximum activity at 60 °C. α-amylases and lipases showed their maximum activities at 50 °C. The maximum alkaline protease and α-amylase activities were found at pH 7 to 9. The enzymatic activity of juvenile's acid proteases was highly inhibited by Pepstatin A (96%), however the activity of alkaline proteases incubated with PHEN, TLCK, SBTI, PMFS, and OVO showed reductions of 51.29, 30.16, 27.98, 27.26, and 24.68% respectively. Lipase activity was totally inhibited with Ebelactone B, and highly inhibited by Ebelactone A, Orlistat, 1% SDS, and PMFS (96.12, 77.16, 64.22, and 51.29%, respectively). Seven bands (102.6, 65.7, 58.9, 40.6, 27.4, 21.5, and 15.8 kDa) resolved by protein electrophoresis were detected with alkaline protease activity, identified as serine proteases and metalloproteases, and three bands (57, 43.9, and 32.6 kDa) with lipase-like activity were also identified. These results show that C. viridis ontogeny entails an indirect development of its digestive system with a functional stomach on day 23, and characterized by increases in pepsin activity. Indeed, white snook ontogeny shows a similar developmental trajectory to other carnivorous marine fish, showing a diversity of alkaline proteases that work in a wide range of pH and temperatures. Thus, the identification of these enzymes provides advantages to formulate white snook aqua-feeds.

Developmental trends in children’s source and destination memory

Destination memory (the ability to remember who one has told information to) has been studied in adult samples, but not with child participants. The goals of the current research were to describe the development of children’s destination memory abilities across early to middle childhood and to compare destination memory with source-monitoring abilities within the same age range. In two studies, children aged 5–10 years had conversations with two puppets and were later asked to recall which puppet they had disclosed specific information to. Study 1 (N = 86) revealed age to be a significant predictor of destination memory accuracy. Study 2 (N = 90) demonstrated that source memory and destination memory were related and shared a similar developmental trajectory but that source accuracy was higher on average than destination accuracy. This research contributes to our theoretical understanding of children’s memory development, and directions for future research are highlighted in the Discussion. Implications for investigative interviews in which children are asked about prior disclosures are discussed.

Late- but not early-onset blindness impairs the development of audio-haptic multisensory integration.

Integrating different senses to reduce sensory uncertainty and increase perceptual precision can have an important compensatory function for individuals with visual impairment and blindness. However, how visual impairment and blindness impact the development of optimal multisensory integration in the remaining senses is currently unknown. Here we first examined how audio-haptic integration develops and changes across the life span in 92 sighted (blindfolded) individuals between 7 and 70years of age. We used a child-friendly task in which participants had to discriminate different object sizes by touching them and/or listening to them. We assessed whether audio-haptic performance resulted in a reduction of perceptual uncertainty compared to auditory-only and haptic-only performance as predicted by maximum-likelihood estimation model. We then compared how this ability develops in 28 children and adults with different levels of visual experience, focussing on low-vision individuals and blind individuals that lost their sight at different ages during development. Our results show that in sighted individuals, adult-like audio-haptic integration develops around 13-15years of age, and remains stable until late adulthood. While early-blind individuals, even at the youngest ages, integrate audio-haptic information in an optimal fashion, late-blind individuals do not. Optimal integration in low-vision individuals follows a similar developmental trajectory as that of sighted individuals. These findings demonstrate that visual experience is not necessary for optimal audio-haptic integration to emerge, but that consistency of sensory information across development is key for the functional outcome of optimal multisensory integration.

Renewal and Differentiation of GCD Necklace Olfactory Sensory Neurons.

Both canonical olfactory sensory neurons (OSNs) and sensory neurons belonging to the guanylate cyclase D (GCD) "necklace" subsystem are housed in the main olfactory epithelium, which is continuously bombarded by toxins, pathogens, and debris from the outside world. Canonical OSNs address this challenge, in part, by undergoing renewal through neurogenesis; however, it is not clear whether GCD OSNs also continuously regenerate and, if so, whether newborn GCD precursors follow a similar developmental trajectory to that taken by canonical OSNs. Here, we demonstrate that GCD OSNs are born throughout adulthood and can persist in the epithelium for several months. Phosphodiesterase 2A is upregulated early in the differentiation process, followed by the sequential downregulation of β-tubulin and the upregulation of CART protein. The GCD and MS4A receptors that confer sensory responses upon GCD neurons are initially expressed midway through this process but become most highly expressed once CART levels are maximal late in GCD OSN development. GCD OSN maturation is accompanied by a horizontal migration of neurons toward the central, curved portions of the cul-de-sac regions where necklace cells are concentrated. These findings demonstrate that-like their canonical counterparts-GCD OSNs undergo continuous renewal and define a GCD-specific developmental trajectory linking neurogenesis, maturation, and migration.

Speech development after cochlear implantation in infants with isolated large vestibular aqueduct syndrome

Background: Few studies on speech performance of children after cochlear implantation (CI) described isolated large vestibular aqueduct syndrome (LVAS).Objective: To investigate speech developmental trajectories of infants with LVAS after CI, and to compare with those who have structurally normal inner ears.Materials and methods: 1112 infants with congenital severe to profound hearing loss participated in this study. 150 infants in group A were diagnosed with LVAS, 962 infants in group B with structurally normal inner ear. The speech performance was assessed via the Meaningful Use of Speech Scale (MUSS). The evaluations were performed pre-implant, 1, 3, 6, 9, 12, 24, 36, 48 and 60 months after CI.Results: The mean scores of the MUSS improved over a 5-year period after implantation in both groups A and B. The LVAS group presented similar speech developmental trajectory to the non-LVAS group at each assessment interval, except pre-operation. There were significant differences in mean scores between vocalizing behavior and oral communication skills, clarification skills of infants in both two groups.Conclusions and significance: Speech performance of infants with LVAS developed rapidly after CI and was similar to infants with structurally normal inner ear. For infants with isolated LVAS, CI had a significant effect and should be recommended as a therapeutic option.

Prevalence of face recognition deficits in middle childhood.

Approximately 2-2.5% of the adult population is believed to show severe difficulties with face recognition, in the absence of any neurological injury-a condition known as developmental prosopagnosia (DP). However, to date no research has attempted to estimate the prevalence of face recognition deficits in children, possibly because there are very few child-friendly, well-validated tests of face recognition. In the current study, we examined face and object recognition in a group of primary school children (aged 5-11 years), to establish whether our tests were suitable for children and to provide an estimate of face recognition difficulties in children. In Experiment 1 (n = 184), children completed a pre-existing test of child face memory, the Cambridge Face Memory Test-Kids (CFMT-K), and a bicycle test with the same format. In Experiment 2 (n = 413), children completed three-alternative forced-choice matching tasks with faces and bicycles. All tests showed good psychometric properties. The face and bicycle tests were well matched for difficulty and showed a similar developmental trajectory. Neither the memory nor the matching tests were suitable to detect impairments in the youngest groups of children, but both tests appear suitable to screen for face recognition problems in middle childhood. In the current sample, 1.2-5.2% of children showed difficulties with face recognition; 1.2-4% showed face-specific difficulties-that is, poor face recognition with typical object recognition abilities. This is somewhat higher than previous adult estimates: It is possible that face matching tests overestimate the prevalence of face recognition difficulties in children; alternatively, some children may "outgrow" face recognition difficulties.

A longitudinal analysis of the attention networks in 6- to 11-year-old children

ABSTRACTAttention is critical for everyday functioning. Posner and Petersen’s model of attention describes three neural networks involved in attention control—the alerting network for arousal, the orienting network for selecting sensory input and reorienting attention, and the executive network for the regulatory control of attention. No longitudinal research has examined relative change in these networks in children. A modified version of the attention network task (ANT) was used to examine changes in the three attention networks, three times over 12 months, in 114 6-, 8- and 10-year-olds. Findings showed that the alerting network continued to develop over this period, the orienting network had stabilized by 6 years, and the conflict network had largely stabilized by 7 years. The reorienting of attention was also assessed using invalid cues, which showed a similar developmental trajectory to the orienting attention network and had stabilized by 6 years. The results confirm that age 6 to 7 years is a critical period in the development of attention, in particular executive attention. The largest improvement over the evaluation period was between 6 and 7 years; however, subtle changes were found in attention beyond 8 years of age.

Sex differences in the behavior of wild Alouatta caraya infants.

Several primates show sex-based differences in activity patterns and social interactions during infancy. These differences have been associated with adult social and reproductive functions of males and females and are related to male-male competition. Our goal was to describe behavioral patterns of wild Alouatta caraya male and female infants, a species with sexual dimorphism in body size and behavioral strategies during adulthood. We also examined the relationship between life history variables, infant sex and age, activity patterns, and social interactions in order to determine whether males and females follow different trajectories during early growth. Over a 27-month study, we observed 21 male infants and 14 female infants across two similar sites in northern Argentina. Data were analyzed using generalized linear mixed model (GLMM) tests. We found no differences in suckling time or weaning age between males and females (9.7 vs. 9.4months), but male infants spent more time feeding on solid food and resting than female infants. Males also invested more time in contact with their mothers than did female infants, and mothers rejected and broke contact with males more frequently than with females. Other behavioral categories did not differ between the sexes. Our results suggest that higher nutritional demands of males compared with females may affect some behaviors. However, mothers of sons did not experience immediate trade-offs between current and future reproduction. Other behaviors, similarly expressed by the two sexes, suggest a similar developmental trajectory between male and female A. caraya infants, meaning that most differences emerge following the infant period.

The femoral ontogeny and long bone histology of the Middle Triassic (?late Anisian) dinosauriform Asilisaurus kongwe and implications for the growth of early dinosaurs

ABSTRACTThe ontogeny of early-diverging dinosauromorphs is poorly understood because few ontogenetic series from the same species-level taxon are known and what is available has not been extensively documented. The large numbers of skeletal elements of the silesaurid Asilisaurus kongwe recently recovered from Tanzania provide an opportunity to examine the ontogenetic trajectory of the earliest known member of Ornithodira and one of the closest relatives to Dinosauria. We examined the ontogeny of the femur and the histology of a series of long bone elements. We observed bone scar variation in a series of femora (n = 27) of different lengths (73.8–177.2 mm). We hypothesize that most femora follow a similar developmental trajectory; however, we observed sequence polymorphism in the order of appearance and shape of bone scars, and we quantified this polymorphism using ontogenetic sequence analysis (OSA). Additionally, five femora, three tibiae, a fibula, and a humerus were thin-sectioned to examine osteological tissues. No lines of arrested growth (LAGs) are present in any specimen, and there is little histological information about the ontogenetic stage of femora, although none have slowed or ceased growth. The woven-fibered bone present in the cortex of elements sectioned is similar to that of the earliest dinosaurs. This sequence polymorphism provides an alternate hypothesis for the robust/gracile dichotomy found in early dinosaurs often interpreted as sexual dimorphism. The shared femoral features found in Asilisaurus and early dinosaurs suggest that this ontogenetic pattern is plesiomorphic for Dinosauria, and that size is a poor predictor of maturity in early dinosauriforms.SUPPLEMENTAL DATA—Supplemental materials are available for this article for free at www.tandfonline.com/UJVPCitation for this article: Griffin, C. T., and S. J. Nesbitt. 2016. The femoral ontogeny and long bone histology of the Middle Triassic (?late Anisian) dinosauriform Asilisaurus kongwe and implications for the growth of early dinosaurs. Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2016.1111224.

The development of face and object processing in childhood

There has been much debate over whether face and object recognition develop at a different rates during childhood. Some researchers suggest that face processing is not mature until the early teenage years, far later than object recognition; others suggest that face recognition is mature relatively early (by 5 yrs), and subsequent improvements reflect more general cognitive development. Recently, it has been suggested that both ideas are correct, but that face memory and face matching develop at different rates. This study addressed this hypothesis by examining face and object (bicycle) matching and memory in primary school children (5-11 yrs). In the memory test, children were asked to learn 4 or 6 faces and bikes; in the matching test, children completed a 3AFC simultaneous matching task. Both memory (N = 134) and matching (N = 432) showed significant improvements with age, but neither task showed an interaction between age and object – that is, memory and perception of faces showed a similar developmental trajectory to general object memory and perception. This suggests that both face memory and face matching are mature early in childhood (< 5yrs), and subsequent increases in performance are related to general cognitive development rather than face-specific processes.

Children's learning of number words in an indigenous farming-foraging group.

We show that children in the Tsimane', a farming-foraging group in the Bolivian rain-forest, learn number words along a similar developmental trajectory to children from industrialized countries. Tsimane' children successively acquire the first three or four number words before fully learning how counting works. However, their learning is substantially delayed relative to children from the United States, Russia, and Japan. The presence of a similar developmental trajectory likely indicates that the incremental stages of numerical knowledge - but not their timing - reflect a fundamental property of number concept acquisition which is relatively independent of language, culture, age, and early education.