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Objectives We present a novel method to estimate original crown height (OCH) for worn human mandibular canines using a cubic regression equation based on ratios of worn crown height and exposed dentin. This method may help alleviate issues frequently presented by worn teeth in dental analyses, including those in bioarchaeology. Materials and Methods Mandibular canines (n = 28) from modern day New Zealand and English populations were selected. Crown height and dentin thickness were measured on dental thin sections (n = 19) and the resulting ratios (log10) were fitted to a cubic regression curve allowing OCH in worn crowns to be predicted. Variation in the dentin apex position was recorded and effects of angled wear slopes investigated allowing adjusted values to be generated. Our method is trialed for use on intact and sectioned teeth (n = 17). Results A cubic regression curve best describes the relationship between (log10) ratios and crown height deciles (R2 = 0.996, df1=3, df2 = 336, p 0.05), with a mean absolute error of 0.171 mm and an adjusted coefficient of determination of 0.923. Conclusion Our approach offers a quantitative method to estimate the percentage of OCH remaining on worn mandibular canines, and by extension, the original crown height. Our estimates are comparable to digitally recreated cusps but are less subjective and not limited to crowns with minimal wear.

Objective: To investigate and describe the variation in enamel daily secretion rates (DSRs) of naturally exfoliated deciduous molars (n = 345) from five modern-day populations (Aotearoa New Zealand, Britain, Canada, France, and Sweden). \ud \ud Design: Each tooth was thin sectioned and examined using a high-powered Olympus BX51 microscope and DP25 digital microscope camera. Mean DSRs were recorded for the inner, mid, and outer regions of cuspal and lateral enamel, excluding enamel nearest the enamel-dentin junction and at the outermost crown surface.\ud \ud Results: Mean DSRs did not vary significantly between populations, or by sex. Cuspal enamel grew slightly faster than lateral enamel (mean difference 0.16 µm per day; p < 0.001). The trajectory of DSRs remained relatively constant from inner to outer cuspal enamel and increased slightly in lateral enamel (p = 0.003). \ud \ud Conclusions: The DSRs of deciduous molars from modern-day children are remarkably consistent when compared among populations. While growth rates are faster in cuspal than lateral enamel, the trajectory of enamel formation changes only slightly from inner to outer regions. The trajectory of DSRs for deciduous molars differs to that of permanent molar enamel, which typically display a steep increase in matrix deposition from inner to outer enamel.

Identifying the individuals who make up burned and commingled skeletal assemblages represents a labour-intensive challenge. Portable X-ray fluorescence (pXRF) is a potential tool for reconciling fragmented and mixed individuals using the unique elemental content of bone. While the method’s usefulness has been demonstrated with unburned bone, further work is needed to identify if the elemental signatures embedded in bone remain consistent enough, regardless of exposure temperature, to allow the discrimination of burned individuals. We test whether pXRF can discriminate between individuals with variable degrees of burning and further, whether the elemental profiles reliably reflect burning temperatures. Tibiae and femora from five fresh lambs (Ovis aries) were sectioned and experimentally burned for 30 min at 200 °C, 400 °C, 600 °C, 800 °C and 900 °C. Elemental profiles from the unburned and burned fragments were analysed using discriminant function analysis. Whether burned, unburned or variably exposed to heat, fragments from the five individuals were successfully distinguished using aggregate elements (more than 80% of fragments correctly classified). The elemental profiles did vary by degree of burning allowing the distinction of fragments burned at 90% correctly classified). Collectively, these results show the promise of pXRF in the analysis of burned and commingled assemblages if the elements used are carefully considered and aggregated. However, further work considering diagenetic effects needs to be undertaken.

Objectives: Human tooth enamel retains evidence of growth in the form of Retzius lines. The number of daily growth increments between the regularly occurring lines defines their repeat interval, or periodicity. Retzius periodicity is often incorporated into enamel formation times, age-at-death reconstructions, or used to provide a basis from which to explore an underlying biorhythm. Biological anthropologists typically assume that RP remains constant within an individual and does not vary along the tooth-row. Here, we test that assumption. Materials and methods: RP was calculated from n = 223 thin sections of human permanent teeth from individuals of British and southern African origin. Forty individuals provided multiple teeth (n = 102 teeth) and a further 121 individuals each provided a single tooth. Results: We report first evidence that RP of permanent teeth does not always remain constant within an individual. Of those individuals that provided multiple teeth, 42% (n = 17/40) demonstrated a decrease in RP along the tooth row, with most shifting by two or more days (n = 11). Across the entire sample, mean RP of anterior teeth was significantly higher than molars. Mean premolar RP tended to be intermediate between anterior teeth and molars.Discussion: Our data do not support the assumption that RP invariably remains constant within the permanent teeth of an individual. Transferring RP from molars to incisors within an individual can result in a miscalculation of formation time and age-at-death by up to one year. Implications for biological anthropologists and the source of the underlying long period biorhythm are discussed.

Previous research proposes stress as a mechanism for linking social environments and biological bodies. In particular, non-human primate studies investigate relationships between cortisol as a measure of stress response and social hierarchies. Because human social structures often include hierarchies of dominance and social status, humans may exhibit similar patterns. Studies of non-human primates, however, have not reached consistent conclusions with respect to relationships between social position and levels of cortisol. While human studies report associations between cortisol and various aspects of social environments, studies that consider social status as a predictor of stress response also report mixed results. Others have argued that perceptions of social status may have different implications for stress response depending upon social context. We propose here that characteristics of children’s social networks may be a better predictor of central tendencies and variability of stress response than their perceptions of social status. This is evaluated among 24 children from 9.4 to 11.3 years of age in one upper middle-class New Zealand primary school classroom, assessed through observation within the classroom, self-reports during semi-structured interviews and 221 serial saliva samples provided daily over 10 consecutive school days. A synthetic assessment of the children’s networks and peer-relationships was developed prior to saliva-cortisol analysis. We found that greater stability of peer-relationships within groups significantly predicts lower within-group variation in mid-morning cortisol over the two-week period, but not overall within-group differences in mean cortisol.

Objective This study evaluates how adjusting for parental height dimorphism influences height differences among parents and same-sex offspring distinguished by parents' early backgrounds. Participants and methods Regression analyses using data from independent groups of Taiwanese families, 56 with sons and 51 with daughters, evaluate how adjusting for parental height dimorphism influences same-sex parent-offspring height differences among families grouped by grandfathers' occupations into three status categories reflecting good to relatively poor early parental environments. Results Parental height dimorphism was statistically significantly associated with same-sex parent-offspring height differences (father–son: mean Δ = 3.88 cm, β = −71.47 ± 11.49 SE, t = −6.22, p ≤ .0005; mother–daughter: mean Δ = 4.15 cm, β = 80.46 ± 18.52 SE, t = 4.35, p ≤ .0005). Adjusted mean father–son differences increased significantly across grandfathers' occupation categories (Privileged, Δ = 0.60, Business, Δ = 4.06, Farming & Labor, Δ = 5.28; p = .011). Mother–daughter differences were substantial, from 3.33 cm to 5.06 cm, but did not differ significantly across occupational categories (p = .63). Discussion Adjustments here for variation in parent height dimorphism did not alter original interpretations that while female growth may be more canalized, it is similarly capable of responding to improvements in developmental contexts. Patterns of same-sex parent-offspring height differences across grandfathers' occupational categories remain best accounted for by Taiwan's rapidly expanding economy, substantial income equity and reductions in biases favoring sons over daughters. Adjustment for sub-group variation in parental height dimorphism should be considered in similar studies in the future.

Accurate age estimations for enamel formation and the timing of enamel hypoplasia have traditionally only been available through histological analyses of dental thin sections, which is a difficult and destructive process. However, an association between striae of Retzius periodicity, crucial for accurate aging, and the total number of striae in imbricational enamel has been reported in the literature. This means periodicity can be estimated nondestructively but is reliant on all perikymata being visible along the crown surface. Therefore, crowns with worn or damaged surfaces may not be able to be assessed, potentially limiting sample sizes. We tested this relationship in a modern New Zealand sample and investigated whether reliable associations might be identified using only partial perikymata counts from the cervical half of the crown. Using mandibular canines (n = 11), the distribution of perikymata per decile was recorded using high definition replica surfaces. Thin sections of the same crowns were used to assess periodicity histologically along with striae of Retzius distributions. A strong correlation between total striae numbers and periodicity was also identified in our sample. Furthermore, we report strong correlations that allow periodicity to be estimated from perikymata counts using only 10% of crown height when certain deciles are used. Based on these findings, we propose a simple matrix that can be developed for nondestructively estimating periodicity based on the range of perikymata counts in the sixth to ninth deciles.

This study evaluates height loss during the day in light of variables assessable through participant self-report. Participants were 19 female and 15 male staff and students who met with us twice with a mean interval between measurement sessions of 6.96h (SD=0.86). Hypotheses were evaluated using two-stage least squares regression analysis (SYSTAT 10). Males and females lost similar amounts of height between sessions (male,x¯=6.9mm;female,x¯=7.4mm). Among factors considered to impact overall height loss, sleep duration (Adj. R2=0.181, p=0.022) and height (Adj. R2=0.121, p=0.048) were useful in univariate analyses, though they were not significant in any models that included variables other than sex. Judging from log-transformed BMI variation, heavier males and females lost more height (F(2, 31)=4.59, Adj. R2=0.179, p=0.018). Among factors anticipated to reduce height loss by acting prior to morning measurements, only time spent walking was significantly associated (β=2.6±0.8mm, t=3.16, p=0.004) when included as a predictor along with sex (p=0.17) and log-BMI (p=0.003). This model explained about 38% of height loss variance. None of the factors considered as potentially acting between measurement sessions showed statistically significant influences when included in the model just described, though predictor coefficients were in the anticipated direction. Results suggest that self-reported activities may be an important supplement to anthropometric studies, both for planning and later evaluation, particularly in large studies.

Objectives This study investigates allometric changes in shoulder breadths relative to changes in stature arising from rapidly changing developmental circumstances within 107 Taiwanese families. It speaks to broader issues related to the extent of phenotypic plasticity of body breadths humans are capable of in response to reductions in developmental stressors. Methods An examination of relationships between shoulder breadth and height within individuals in each generation was followed by evaluation of patterns of difference between same-sex parent–offspring pairs in height and shoulder breadth. Results Height was similarly positively correlated with shoulder breadth within fathers, mothers, sons, and daughters (P ≤ 0.002). Variance accounted for ranged from an adjusted R2 of 0.201 among fathers to 0.151 for sons, with mothers' and daughters' values being 0.187 and 0.181, respectively. Comparisons of differences within families indicate that parents who were shorter than their same-sex offspring also tended to have modestly narrower biacromial breadths (father–son pairs: adjusted R2 = 0.112; t = 2.82, P = .007; mother–daughter pairs: adjusted R2 = 0.135; t = 2.97, P = 0.005). Conclusions Taken as a whole, results here support the view that secular changes in stature are not accompanied by similar changes in body breadths, perhaps so that responses to developmental environmental improvements do not alter thermoregulatory equilibria that reflect long-term evolutionary processes. These results indirectly constrain plausible hypotheses about how ancestors of Austronesian speakers altered their body size and shape as they voyaged to Fiji, Western Polynesia, and beyond.

The role of the distinctive Mongolian Bronze Age mounds (khirigsuurs) has been debated for many years with authors divided over their funerary role. Interpretation of the presence or absence of human bone has been central to this debate. In this paper, we undertake a systematic analysis of human taphonomy at the Khovsgol site to explain why mounds appear “empty”. In doing so we demonstrate a strong statistical relationship between the preservation of human bone and intrinsic circumstances related to the mound locations and the age of the deceased. In contrast, patterns of disarticulation are strongly correlated with human disturbance of graves post-mortem. We argue that statistical analysis of burials, recognising the continuity of potential preservation from nil to complete serves to explain the relative importance of taphonomic agents but allows for predictive analysis of where remains are most likely to be preserved. Such approaches are important in shifting studies of human taphonomy from a descriptive to analytical endeavour.

Investigating past human-environment interactions requires not only suitable environmental proxies and well-dated archaeological records, but also a uniform temporal resolution between the two. In the arid interior of Australia, the archaeological record of human occupation is known only from relatively few locations, and palaeoenvironmental records with resolution on timescales akin to human lifetimes are rare. Even where detailed archaeological and palaeoenvironmental studies have been undertaken concurrently, it has proven difficult to match the temporal resolution of both the archaeological and sedimentary records. One approach is to make use of the extensive surface archaeological record and match it to high-resolution palaeoenvironmental records from elsewhere. Here, we utilise radiocarbon age determinations on charcoal from the deflated remains of heat retainer hearths from surface archaeological contexts in western NSW. Correlations with two different but related sets of environmental proxy data (sea surface temperature fluctuations from the western Pacific/South China Sea and Australian dust deposition records from southern New Zealand) allow investigation of human responses to global environmental changes at a common temporal scale. The correlations suggest a relationship between rapid climatic changes occurring over the last 3000 years and occupation by Aboriginal people in the arid region of western New South Wales. Aboriginal people abandoned large regions during times of lower rainfall and increased dust transport, with some but not all regions reoccupied during periods of increased summer rainfall. Environmental fluctuations during the late Holocene are likely to have posed marked challenges for Aboriginal populations who occupied the region. The patterns of radiocarbon assays from hearths provide a window into the nature of their response.

Recent studies make use of cortex proportion as a proxy measurement for the impact of artefact transport on assemblage formation. Cortex in these studies is measured on an ordinal scale and analysed in relation to mechanical measurements of artefact size. Here we report on the use of a 3D laser scanner to obtain precise measurements from experimental lithic reduction sets. High-resolution measurements of cortex area are compared to measurements obtained through ordinal approximations of cortex proportion and mechanical approximations of artefact size. While the ordinal and mechanical measurements result in considerable error for individual artefacts, estimates improve significantly as sample size increases.

OBJECTIVE This study evaluates competing hypotheses about implications of greater female growth canalization for differences in male and female growth as developmental settings improve. PARTICIPANTS AND METHODS Intergenerational declines in gender bias and rapid economic growth in Taiwan permit assessment of the two hypotheses using anthropometric and background information from 107 Taiwanese parents and their young adult offspring. Differences in parents' values were first evaluated across grandfathers' occupational status categories reflecting good to relatively poor early circumstances in the parental generation. The extent of intergenerational change in heights or knee heights within 56 father-son pairs were then compared with those in 51 statistically independent mother-daughter pairs across the same occupational categories using repeated measures analyses. RESULTS Change in mean heights and knee heights across grandfathers' occupational categories were noticeably greater for fathers than mothers. Overall, intergenerational gains within families in height and knee height were statistically significant (p

Adopted children often experience health and well-being disadvantages compared to biological children remaining in their natal households. The degree of genetic relatedness is thought to mediate the level of parental investment in children, leading to poorer outcomes of biologically unrelated children. We explore whether mortality is related to adoption in a historical Taiwanese population where adoption rarely occurred among kin. Using Cox proportional hazards models in which adoption is included as a time-dependent covariate, we show that adoption of girls does not increase the risk of mortality, as previously suggested; in fact, it is either protective or neutral with respect to mortality. These results suggest that socio-structural variables may produce positive outcomes for adopted children, even compared to biological children who remain in the care of their parents.

Researchers have hypothesized that shorter mean statures at onset of the adolescent spurt and more rapid skeletal maturation during adolescence among East Asian populations contribute significantly to their shorter mean adult statures compared to European populations. The goal of this study is to use longitudinal height growth data modeled with the Preece-Baines Model 1 (PB1) function to examine the relative importance of adolescent growth to population differences in adult stature. Biological variables for 303 Chinese females from the Da-an District in Taipei, Taiwan, are compared with those for 23 British and 69 Euro-American females. Results indicate that 96% of the difference in adult statures (4.37 cm) between the British and urban Chinese may be attributed to the greater amount of time available to the British for preadolescent growth. Growth during adolescence between these two groups is not significantly different. When comparisons are made with the Euro-American sample from Berkeley, California, only about 26% of the difference in adult stature (6.96 cm) may be attributed to the later age at take-off. Much (53.2%) of the difference has already accrued by take-off among the Chinese. Small, but statistically significant differences in adolescent growth also exist. When considered within the context of other longitudinal studies of European and American females, this study gives only modest support to the hypothesis that more rapid skeletal maturation leads to reduced amounts of adolescent growth among East Asian populations. Interestingly, though, population differences do appear to exist in the relationship between the relative timing of an individual's growth spurt and spurt intensity. Am. J. Hum. Biol. 10:735-746, 1998. © 1998 Wiley-Liss, Inc.

Accurate age estimations for enamel formation and the timing of enamel hypoplasia have traditionally only been available through histological analyses of dental thin sections, which is a difficult and destructive process. However, an association between striae of Retzius periodicity, crucial for accurate aging, and the total number of striae in imbricational enamel has been reported in the literature. This means periodicity can be estimated nondestructively but is reliant on all perikymata being visible along the crown surface. Therefore, crowns with worn or damaged surfaces may not be able to be assessed, potentially limiting sample sizes. We tested this relationship in a modern New Zealand sample and investigated whether reliable associations might be identified using only partial perikymata counts from the cervical half of the crown. Using mandibular canines (n = 11), the distribution of perikymata per decile was recorded using high definition replica surfaces. Thin sections of the same crowns were used to assess periodicity histologically along with striae of Retzius distributions. A strong correlation between total striae numbers and periodicity was also identified in our sample. Furthermore, we report strong correlations that allow periodicity to be estimated from perikymata counts using only 10% of crown height when certain deciles are used. Based on these findings, we propose a simple matrix that can be developed for nondestructively estimating periodicity based on the range of perikymata counts in the sixth to ninth deciles.

Enamel extension rates (EERs), the rates at which ameloblasts differentiate, determine how fast tooth crowns grow in height. Studies of fossil primate (including hominin) enamel microstructure usually focus on species differences in enamel formation time, but they have also begun to address species-level variation in enamel extension rates. To improve our ability to compare EERs among primate species, a better understanding how EERs vary within species is necessary. Using a large and diverse modern human histological sample, we find that initial EERs and patterns of EER change along the enamel-dentine junction (EDJ) vary in relation to EDJ length. We also find that enamel formation time varies in relation to EDJ length, but that it does so independently of initial EERs. These results suggest that EDJ length variation within a species sample can affect interspecific comparisons not only of EERs but also of enamel formation times. Additionally, these results lend within-species support to the hypothesis, based on comparisons among hominin species, that EERs and crown formation times can vary independently (Dean, 2009). In a second approach, we analyzed EER changes specifically in the lateral enamel of two modern human population samples as these changes relate to the distribution of perikymata. As surface manifestations of internal enamel growth increments, perikymata provide a valuable source of information about enamel growth in fossils. We find that EER declines in the lateral enamel are associated with an increase in perikymata density from first to last-formed lateral enamel. Moreover, variation in the extent of EER decline among individuals is associated with variation in the distribution of perikymata along their enamel surfaces. These latter findings suggest that the distribution of perikymata on the enamel surface provides information about rates of EER decline in lateral enamel, at least in modern humans.

In this study, heights, weights, and numbers of decayed, extracted, and filled (DEF) deciduous teeth of 300 first-graders from a less affluent area of Taipei were compared with those of 277 first-graders from a more affluent one. Parents of all children self-identified as having ancestors from Fujian. This study tested the hypothesis that synergisms between under-nutrition and disease form part of a causal pathway contributing to the risk of deciduous caries. Within the less affluent community significant inverse associations between height and body mass index, as proxies for nutritional status, and the frequency of DEF deciduous teeth were anticipated. These associations were not expected in the more affluent community where nutritional status was adequate. An alternative hypothesis, that parental behavior potentially correlated with parental education, occupational backgrounds, housing, or family size contributed independently to offspring nutritional status and caries risk, was evaluated with available data. Consistent with the primary hypothesis, regression analyses revealed significant negative slopes of height (P = 0.002) and log BMI (P = 0.036) on total DEF deciduous teeth in the less affluent group, but not in the more affluent one. Direct tests of slope coefficients in the two groups indicate a significant difference for height (P = 0.041) but not log BMI (P = 0.29). Inclusion of parental education, occupational categories, housing, and numbers of siblings in the regression model provided no support to the alternative hypothesis. Results suggest that improving nutritional status significantly lowers caries risk, though most variation is probably attributable to other factors.

Evidence indicates that variation in relative leg length (RLL) is a sensitive indicator of early childhood circumstances, but research presents conflicting evidence of how lower leg growth contributes to variability. This study investigates the extent of intergenerational changes in subischial leg length and knee height relative to stature among father–son, mother–daughter, and midparent–offspring pairs. These changes and differences in the extent of mean change in the two indices within like-sex parent–offspring pairs were assessed using repeated measures ANOVA. Results indicate that within all categories, mean generational differences in both indices were substantial [Δ RLL z: 0.64–0.73; Δ relative knee height (RKH) z: 0.46–0.64] and statistically significant (P ≤ 0.010). Mean increases in RLL and RKH across parent–offspring categories were consistently greater in Taipei than Auckland, though only the midparent–offspring generation by location contrast for RLL was statistically significant (P = 0.037). Father–son and mother–daughter average differences were virtually identical for RLL (0.73 z vs. 0.72 z). When differences within pairs in the extent of change in RLL and RKH were assessed directly, mother–daughter mean differences approached significance at an α level of 0.05 (Δ = 0.26 z; F = 3.42, df = 1, 42, P = 0.071). Father–son differences were smaller (Δ = 0.09 z) and statistically insignificant suggesting very similar amounts of change in the two indices. Am. J. Hum. Biol., 2008. © 2008 Wiley-Liss, Inc.

This study first examines the hypothesis that significant intergeneration increases in stature within 85 Taiwanese families in two study locations were primarily the result of increases in subischial leg length. It then evaluates a second hypothesis that independent assessments of the extent of intergenerational change in childhood environments within these families helped account for parent–offspring differences in relative leg length. Childhood environments were assessed using two criteria: developmental environment scores derived from life history data and evidence of linear enamel hypoplasia (LEH). Relative leg length was represented in two ways, as either the difference between internally estimated sex-specific z-scores of sitting height and subischial leg length (zD = zSH − zLL) or as relative sitting height (RSH; sitting height/height × 100). Paired Student t tests indicated intergenerational increases in relative leg length were significantly greater than zero in both study locations (P ≤ 0.012). The second hypothesis, tested using a hierarchical model with maximum likelihood estimation that allowed for nesting of more than one offspring per family, received support as midparent–offspring differences in composite scores were significantly positively associated with midparent–offspring differences in relative leg length. This was true alone (P = 0.018), and when significant associations with LEH prevalence among mothers and offspring were statistically controlled for (P = 0.010). Evidence also indicated that while the large majority of offspring were taller than their midparental average height (84.3%; 91/108), offspring who were taller were also more likely to have relatively longer legs than by chance alone (Fishers exact, P = 0.027).Am. J. Hum. Biol. 19:358–375, 2007. © 2007 Wiley-Liss, Inc.

While much is strongly suspected about synergisms linking courses of growth and development with nutrient intakes, immune function, disease exposures, and energy expenditures, debates remain regarding the probability of permanent impairments to growth and function under various circumstances.This study tests a series of related hypotheses in an attempt to reconcile evidence of increasing physiological stress among Warlpiri and Pintubi infants and young children following settlement in the 1940s with their frequently rapid and undelayed longitudinal growth in stature during adolescence.The study used archived cross-sectional and longitudinal records of stature, weight, and dental casts collected by the Dental School at the University of Adelaide beginning in 1951 at the then recently settled community of Yuendumu. Longitudinal modelling of height data and all statistical tests were accomplished using SYSTAT 10. Height, weight, and BMI (kg m-2) for age z-scores were calculated using NCHS reference data. Dental casts were scored for linear enamel hypoplasia (LEH) with each defect assigned to an enamel developmental unit. The extent of height catch-up was estimated using conditional height gain.Cross-sectional analyses indicate significant associations between birth year and women's heights (n = 105, p = 0.02) or height for age z-scores (p = 0.003), but no similar associations among men. Final height for age z-score was significantly associated with sex (p0.0005), onset (p = 0.031), and an onset by number of enamel defects interaction (p = 0.033). Late adolescent height z-scores were only significantly negatively associated with increasing numbers of defects among individuals with enamel defects appearing prior to about 18 months of age (n = 60, p = 0.019). With longitudinally estimated age at peak height velocity (APHV) statistically controlled, peak height velocity (PHV) was similarly significantly positively associated with conditional height gain in males (n = 50, p = 0.01) and females (n = 31, p = 0.05). Exploratory analyses suggest that with timing and intensity of PHV controlled, childhood body mass was only significantly positively associated with catch-up in height among those who experienced defect onset relatively early (n = 80, p = 0.005).Results help explain previously documented, and apparently contradictory, outcomes of settlement processes. Rapid and relatively undelayed late childhood and adolescent growth associated with catch-up in height occurred through a confluence of increasing early childhood systemic stress followed by increases in net energy consumption that probably increased as children aged.

Surveys reveal that Chinese from the southernmost provinces are, on average, consistently shorter and lighter than their peers in provinces to the north, though explanations for this variation differ. The present study helps to distinguish between genetic and developmental explanations by comparing differences in regional and provincial heights and weights of 3184 children born in Taiwan between 1975 and 1980 whose families had emigrated from different regions of China at varying times in the past, but who all lived in a relatively affluent district in Taipei at the time of measurement. Linear regression analyses adjusted heights for measurement age and relevant (and available) socioeconomic and demographic variables. Results of these analyses suggested that clinal genetic variation is an important contributor to regional differences in China. Whether entering primary school or departing middle school, children of northern Chinese ancestry living in Taipei were significantly taller (males, 25–30 mm, p ⩽0.014; females, 18 mm; p ⩽0.008) and heavier (males, 2.5–3.8 kg; p ⩽0.081; females, 0.9–3.4 kg, p ⩽0.046) than those of southern ancestry, with those from central provinces intermediate in most comparisons. Additionally, provincial backgrounds of Taipei middle school girls with family origins in 12 provinces across China and in Taiwan were significantly associated with height ( n =905; p =0.003) and weight ( n =900; p =0.001). The pattern of change in mean values across provinces of origin suggests that as developmental circumstances become more equal for residents of various provinces in China, already documented declines in mean height differences, particularly in some central and southern provinces, will shrink further.

It has been argued that patrilineal joint family systems tend to bias family planning decisions in favour of sons. A simple model suggests that in such societies, any given son will be more highly valued by his parents (1) the fewer his brothers and (2) the earlier his birth is in the brother series. A daughter's value will be greater (1) the fewer brothers she has and (2) the earlier her birth is relative to other sisters. This study first addresses the extent of son preference as inferred from family composition data for 772 Taiwanese first-graders born in the mid-1970s in two socioeconomically distinct communities in Taipei, Taiwan. It then uses linear regression to consider whether the model criteria help account for statural variation among children in each study area when controlling for differences in measurement age, parental education and housing. With respect to family composition and gender preference, available evidence was consistent with previous surveys. While better-educated parents in the more affluent study area had significantly fewer children (pp≤0·005). Evidence from mean height of males and females partially accords with hypothetical predictions. In the less affluent area, the interaction effect of male birth order and the presence of younger siblings was significantly associated with mean stature (p=0·002). Males without brothers were 2·0 cm taller than males with either an older or a younger brother (116·3 ± 0·5 cm vs 114·3 ± 0·4 cm). Males who had both younger and older brothers, but often no sisters, were about as tall, however, as those without brothers. A similar, but less pronounced, pattern was found amoung males in the more affluent area, but only among those who had sisters. These boys were also consistently shorter than boys without sisters (115·6 ± 0·6 cm vs 117·7 ± 0·6 cm; p=0·001). Patterns of mean female stature did not clearly support the hypothesis. Girls in the more affluent area were relatively tall and did not show significant variation. Results among less affluent girls showed significant contrasts, but not necessarily in the predicted direction.

Cross-sectional heights and weights collected by Taiwan's Ministry of Education since 1964, and reported separately for Taipei and rural townships from 1969 through 1990, were used to test the hypothesis that in Taiwan the degree to which increments of change in height and weight of urban or rural boys and girls tracked each other from year to year was a function of sex and age-related capacities to respond to common environmental forces. Five testable implications follow from this hypothesis. Results were evaluated using detrended time series derived correlations of yearly or near yearly change in sex-specific age group height or weight means within and across regions, cross-sectionally estimated ages of maximum change of height and weight, and evidence of response to two recessions. The hypothesis was largely supported by the available evidence. The similarities in secular change from year to year, with only a few exceptions, suggested that socioeconomic trends indirectly affected the pace of growth of children in both urban and rural Taiwan measured in the spring of the following year. The strength and age-related pattern of these correlations were consistent with sex and age-related capacities to respond to shared environmental factors. Evidence of lags between height and weight, found both in cross-sectionally estimated mean ages of maximum change in height and weight and in the pattern of within sex correlations also argued for the hypothesis. The evidence further suggested that when the economy faltered briefly in Taiwan following worldwide oil crises, children's growth was rapidly affected in an age-dependent manner. This study bolsters the view that secular changes in growth reflect environmental quality. It suggests as well that under some circumstances, environmental change may be rapidly reflected as mean changes in height or weight of certain age groups. The intensity of the response appears to be related to the degree of improvement or deprivation, the maturationally mediated pace of growth, and probably initial energy balance.

This study is based on seven samples of school children (n = 516) from rural (five groups) and urban (two groups) settings in western Maharashtra, India. Height and weight were recorded for each subject. Intra-oral observation of the labial surface of maxillary and mandibular anterior teeth was conducted with a low power (3×) illuminated hand lens. Presence of enamel hypoplasia was recorded on a dental chart by drawing the size and location of the defect on the affected tooth. Data analysis was conducted in two stages: 1) Enamel hypoplasia (EH) prevalence was analyzed by percentage of teeth and by percentage of individuals affected for the composite sample and independently for each study group and 2) an assessment of the relationship between anthropometric variables (height and weight), socio-economic status (SES), and localized hypoplasia of primary canines (LHPC; Skinner, 1986) was evaluated using multiple linear regression analysis. EH was observed less often in deciduous incisors (0.2% in di2 to 2.5% in di2) than in deciduous canines (dc). Mandibular dc were affected with the greatest frequency (23.1%, tooth count). The overall individual count prevalence of dc hypoplasia (LHPC) is 26.2% (134/511) for all village samples and sexes combined. Difference in LHPC frequency by sex is non-significant, with males (24.7%, 70/284) and females (28.2%, 64/227) exhibiting nearly equal values. Significant inter-group variation in LHPC prevalence was documented among the seven groups, and the range of LHPC prevalence the among living groups exceeds variability in LHPC among four prehistoric Chalcolithic skeletal series of the Deccan Plateau. Multiple regression analysis revealed no significant relationship between height-for-age or weight-for-age in four school samples (two urban/two rural), but a significant association between stature and LHPC was found for three rural endogamous groups. Children with LHPC were significantly shorter by 1.5 cm than children who lacked the defect after controlling for differences in age. While the association between low birth weight and EH is strong and well documented clinically, the association between childhood stature and LHPC is more variable across groups and may reflect inter-group variation in the duration and intensity of environmental stress. Am. J. Hum. Biol. 13:788–807, 2001. © 2001 Wiley-Liss, Inc.

This study uses longitudinal height records of girls in two urban and one rural area in Taiwan. Individual height records were modeled with the Preece-Baines Model 1 (PB1) function to test two related hypotheses: 1) Taiwanese students who experienced a relatively stable, affluent growth environment from an early age, as judged from parental education and stability of residence type, will have a pattern of correlations for the timing and intensity of the growth spurt similar to those of European and American females; and 2) those students whose parents gained the wherewithal to move from single-story to multi-story dwellings while they were in primary school will have the most atypical patterns. The extent to which these and other sociodemographic factors influence pubertal spurt velocities and increments of adolescent growth were explored as well using multiple regression analyses. Results support the view that rapid socioeconomic change in Taiwan influenced the relationship between the timing and intensity of adolescent growth in stature. Children in the more stable environments in both urban areas had patterns of correlations typical of population samples from developed countries. The most atypical correlations in both areas were found among those who likely experienced the greatest improvement in socioeconomic status during primary school. These represent positive values previously unreported in the literature. Differences in amounts of growth, though in accord with these patterns, were quite small. Am. J. Hum. Biol. 12:102-117, 2000. Copyright 2000 Wiley-Liss, Inc.