TY - JOUR A1 - Czernitzki, Anna-Franziska A1 - Pospisil, Christina A1 - Musalek, Martin A1 - Mumm, Rebekka A1 - Scheffler, Christiane T1 - Analysis of longitudinal data of height z-scores in kindergarten children BT - a pilot study JF - Journal of biological and clinical anthropology : Anthropologischer Anzeiger ; Mitteilungsorgan der Gesellschaft für Anthropologie N2 - Changes in body height throughout extended historic periods are very complex and dynamic processes. Thispilot study aimed to investigate the pattern of longitudinal height z-scores changes in children before and after entering kindergarten. In summer 2016, we measured height and weight of 32 children from 4 groups of two kindergartens aged 3–6 years. All ages were centered according to the age of entry into the kindergarten. For each child we determined mean z-scores for height before and after entering the kindergarten, and assessed the variances for each kindergarten group. Twenty-two children targeted in height z-scores towards average height of their respective kindergarten group, 10 children did not. Due to the small numbers, the convergence in height variance however, remained insignificant (chi-squared independence test, p = 0.127). Additional studies with larger sample sizes are needed to confirm this pilot study. KW - Height z-score KW - kindergarten children KW - secular trend KW - strategic growth adjustment KW - social signal Y1 - 2017 U6 - https://doi.org/10.1127/anthranz/2017/0708 SN - 0003-5548 VL - 74 IS - 2 SP - 109 EP - 112 PB - Schweizerbart science publishers CY - Stuttgart ER - TY - JOUR A1 - Fritz, Amelie A1 - Makeyeva, Angelina A1 - Staub, Kaspar A1 - Groth, Detlef T1 - Influence of network properties on a migration induced secular height trend by Monte Carlo simulation JF - Journal of biological and clinical anthropology : Anthropologischer Anzeiger ; Mitteilungsorgan der Gesellschaft für Anthropologie N2 - Background: Recent research reported height biased migration of taller individuals and a Monte Carlo simulation showed that such preferential migration of taller individuals into network hubs can induce a secular trend of height. In the simulation model taller agents in the hubs raise the overall height of all individuals in the network by a community effect. However, it could be seen that the actual network structure influences the strength of this effect. In this paper the background and the influence of the network structure on the strength of the secular trend by migration is investigated. Material and methods: Three principal network types are analyzed: networks derived from street connections in Switzerland, more regular fishing net like networks and randomly generated ones. Our networks have between 10 and 152 nodes and between 20 and 307 edges connecting the nodes. Depending on the network size between 5.000 and 90.000 agents with an average height of 170 cm (SD 6.5 cm) are initially released into the network. In each iteration new agents are regenerated based on the actual average body height of the previous iteration and, to a certain proportion, corrected by body heights in the neighboring nodes. After generating new agents, a certain number of them migrated into neighbor nodes, the model let preferentially taller agents migrate into network hubs. Migration is balanced by back migration of the same number of agents from nodes with high centrality measures to less connected nodes. The latter is random as well, but not biased by the agents height. Furthermore the distribution of agents per node and their correlation to the centrality of the nodes is varied in a systematic manner. After 100 iterations, the secular trend, i.e. the gain in body height for the different networks, is investigated in relation to the network properties. Results: We observe an increase of average agent body height after 100 iterations if height biased migration is enabled. The increase rate depends on the height of the neighboring factor, the population distribution, the relationship between population in the nodes and their centrality as well as on the network topology. Networks with uniform like distributions of the agents in the nodes, uncorrelated associations between node centrality and agent number per node, as well as very heterogeneous networks with very different node centralities lead to biggest gains in average body height. Conclusion: Our simulations show, that height biased migration into network hubs can possibly contribute to the secular trend of height increase in the human population. The strength of this "tall by migration" event depends on the actual properties of the underlying network. There is a possible significance of this mechanism for social networks, when hubs are represented by individuals and edges as their personal relationships. However, the required high number of iterations to achieve significant effects in more natural network structures in our models requires further studies to test the relevance and real effect sizes in real world scenarios. KW - secular trend KW - body height KW - simulation KW - community effect KW - Monte Carlo method KW - network KW - centrality measures Y1 - 2019 U6 - https://doi.org/10.1127/anthranz/2019/1032 SN - 0003-5548 VL - 76 IS - 5 SP - 433 EP - 443 PB - Schweizerbart CY - Stuttgart ER - TY - JOUR A1 - Groth, Detlef T1 - Modeling a secular trend by Monte Carlo simulation of height biased migration in a spatial network JF - Anthropologischer Anzeiger : journal of biological and clinical anthropology ; Mitteilungsorgan der Gesellschaft für Anthropologie N2 - Background: In a recent Monte Carlo simulation, the clustering of body height of Swiss military conscripts within a spatial network with characteristic features of the natural Swiss geography was investigated. In this study I examined the effect of migration of tall individuals into network hubs on the dynamics of body height within the whole spatial network. The aim of this study was to simulate height trends. Material and methods: Three networks were used for modeling, a regular rectangular fishing net like network, a real world example based on the geographic map of Switzerland, and a random network. All networks contained between 144 and 148 districts and between 265-307 road connections. Around 100,000 agents were initially released with average height of 170 cm, and height standard deviation of 6.5 cm. The simulation was started with the a priori assumption that height variation within a district is limited and also depends on height of neighboring districts (community effect on height). In addition to a neighborhood influence factor, which simulates a community effect, body height dependent migration of conscripts between adjacent districts in each Monte Carlo simulation was used to re-calculate next generation body heights. In order to determine the direction of migration for taller individuals, various centrality measures for the evaluation of district importance within the spatial network were applied. Taller individuals were favored to migrate more into network hubs, backward migration using the same number of individuals was random, not biased towards body height. Network hubs were defined by the importance of a district within the spatial network. The importance of a district was evaluated by various centrality measures. In the null model there were no road connections, height information could not be delivered between the districts. Results: Due to the favored migration of tall individuals into network hubs, average body height of the hubs, and later, of the whole network increased by up to 0.1 cm per iteration depending on the network model. The general increase in height within the network depended on connectedness and on the amount of height information that was exchanged between neighboring districts. If higher amounts of neighborhood height information were exchanged, the general increase in height within the network was large (strong secular trend). The trend in the homogeneous fishnet like network was lowest, the trend in the random network was highest. Yet, some network properties, such as the heteroscedasticity and autocorrelations of the migration simulation models differed greatly from the natural features observed in Swiss military conscript networks. Autocorrelations of district heights for instance, were much higher in the migration models. Conclusion: This study confirmed that secular height trends can be modeled by preferred migration of tall individuals into network hubs. However, basic network properties of the migration simulation models differed greatly from the natural features observed in Swiss military conscripts. Similar network-based data from other countries should be explored to better investigate height trends with Monte Carlo migration approach. KW - secular trend KW - body height KW - simulation KW - community effect KW - Monte Carlo method KW - network Y1 - 2017 U6 - https://doi.org/10.1127/anthranz/2017/0703 SN - 0003-5548 SN - 2363-7099 VL - 74 IS - 1 SP - 81 EP - 88 PB - Schweizerbart CY - Stuttgart ER - TY - JOUR A1 - Hermanussen, Michael A1 - Scheffler, Christiane T1 - Stature signals status: The association of stature, status and perceived dominance - a thought experiment JF - Journal of biological and clinical anthropology : Anthropologischer Anzeiger ; Mitteilungsorgan der Gesellschaft für Anthropologie N2 - Background: There is a common perception that tall stature results in social dominance. Evidence in meerkats suggests that social dominance itself may be a strong stimulus for growth. Relative size serves as the signal for individuals to induce strategic growth adjustments. Aim: We construct a thought experiment to explore the potential consequences of the question: is stature a social signal also in humans? We hypothesize that (1) upward trends in height in the lower social strata are perceived as social challenges yielding similar though attenuated upward trends in the dominant strata, and that (2) democratization, but also periods of political turmoil that facilitate upward mobility of the lower strata, are accompanied by upward trends in height. Material and methods: We reanalyzed large sets of height data of European conscripts born between 1856-1860 and 1976-1980; and annual data of German military conscripts, born between 1965 and 1985, with information on height and school education. Results: Taller stature is associated with higher socioeconomic status. Historic populations show larger height differences between social strata that tend to diminish in the more recent populations. German height data suggest that both democratization, and periods of political turmoil facilitating upward mobility of the lower social strata are accompanied by a general upward height spiral that captures the whole population. Discussion: We consider stature as a signal. Nutrition, health, general living conditions and care giving are essential prerequisites for growth, yet not to maximize stature, but to allow for its function as a lifelong social signal. Considering stature as a social signal provides an elegant explanation of the rapid height adjustments observed in migrants, of the hitherto unexplained clustering of body height in modern and historic cohorts of military conscripts, and of the parallelism between changes in political conditions, and secular trends in adult human height since the 19th century. KW - community effect on height KW - secular trend KW - body height KW - social signals KW - strategic growth adjustment Y1 - 2016 U6 - https://doi.org/10.1127/anthranz/2016/0698 SN - 0003-5548 VL - 73 SP - 265 EP - 274 PB - Schweizerbart CY - Stuttgart ER - TY - JOUR A1 - Hermanussen, Michael A1 - Scheffler, Christiane T1 - Secular trends in gestational weight gain and parity on birth weight BT - an editorial JF - Acta paediatrica : nurturing the child KW - birth weight KW - gestational weight gain KW - multipara KW - parity KW - primipara KW - secular trend Y1 - 2020 U6 - https://doi.org/10.1111/apa.15678 SN - 0803-5253 SN - 1651-2227 VL - 110 IS - 4 SP - 1094 EP - 1096 PB - Wiley CY - Oxford ER - TY - JOUR A1 - Mumm, Rebekka A1 - Hermanussen, Michael T1 - A short note on the BMI and on secular changes in BMI JF - Human biology and public health N2 - Human size changes over time with worldwide secular trends in height, weight, and body mass index (BMI). There is general agreement to relate the state of nutrition to height and weight, and to ratios of weight-to-height. The BMI is a ratio. It is commonly used to classify underweight, overweight and obesity in adults. Yet, the BMI is inappropriate to provide any immediate information on body composition. It is accepted that the BMI is “a simple index to classify underweight, overweight and obesity in adults”. It is stated that “policies, programmes and investments need to be “nutrition-sensitive”, which means they must have positive impacts on nutrition”. It is also stated that “a need for policies that address all forms of malnutrition by making healthy foods accessible and affordable, while restricting unhealthy foods through fiscal and regulatory restrictions“. But these statements are neither warranted by arithmetic considerations, nor by historic evidence. Measuring the BMI is an appropriate screening tool for detecting an unusual weight-to-height ratio, but the BMI is an inappropriate tool for estimating body composition, or suggesting medical and health policy decisions. KW - body mass index KW - secular trend KW - weight-to-height ratio KW - malnutrition KW - obesity Y1 - 2021 U6 - https://doi.org/10.52905/hbph.v2.17 SN - 2748-9957 IS - 2 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - THES A1 - Scheffler, Christiane T1 - Studies on plasticity within the universal pattern of growth and developmet of children and adolescents N2 - The anatomically modern human Homo sapiens sapiens is distinguished by a high adaptability in physiology, physique and behaviour in short term changing environmental conditions. Since our environmental factors are constantly changing because of anthropogenic influences, the question arises as to how far we have an impact on the human phenotype in the very sensitive growth phase in children and adolescents. Growth and development of all children and adolescents follow a universal and typical pattern. This pattern has evolved as the result of trade-offs in the 6-7 million years of human evolution. This typically human growth pattern differs from that of other long-living social primate species. It can be divided into different biological age stages, with specific biological, cognitive and socio-cultural signs. Phenotypic plasticity is the ability of an organism to react to an internal or external environmental input with a change in the form, state, and movement rate of activity (West-Eberhard 2003). The plasticity becomes visible and measurable particularly when, in addition to the normal variability of the phenotypic characteristics within a population, the manifestation of this plasticity changes within a relatively short time. The focus of the present work is the comparison of age-specific dimensional changes. The basic of the presented studies are more than 75,000 anthropometric data-sets of children and adolescence from 1980 up today and historical data of height available in scientific literature. Due to reduced daily physical activity, today's 6-18 year-olds have lower values of pelvic and elbow breadths. The observed increase in body height can be explained by hierarchies in social networks of human societies, contrary to earlier explanations (influence of nutrition, good living conditions and genetics). A shift towards a more feminine fat distribution pattern in boys and girls is parallel to the increase in chemicals in our environment that can affect the hormone system. Changing environmental conditions can have selective effects over generations so that that genotype becomes increasingly prevalent whose individuals have a higher progeny rate than other individuals in this population. Those then form the phenotype which allows optimum adaptation to the changes of the environmental conditions. Due to the slow patterns of succession and the low progeny rate (Hawkes et al. 1998), fast visible in the phenotype due to changes in the genotype of a population are unlikely to occur in the case of Homo sapiens sapiens within short time. In the data sets on which the presented investigations are based, such changes appear virtually impossible. The study periods cover 5-30 to max.100 years (based on data from the body height from historical data sets). N2 - Der anatomisch moderne Mensch Homo sapiens sapiens zeichnet sich durch eine hohe Anpassungsfähigkeit von Physiologie, Körperbau und Verhalten an sich kurzfristig ändernde Umweltbedingungen aus. Daraus ergibt sich die Frage inwieweit anthropogene Umweltbedingungen die sehr sensible Wachstumsphase von Kindern und Jugendlichen beeinflussen können. Das universelle und für den Menschen typische Wachstums- und Entwicklungsmuster mit unterschiedlichen biologisch, kognitiv und soziokulturell abgrenzbaren Entwicklungsstadien, welches sich in 6-7 Millionen Jahren menschlicher Evolution herausgebildet hat, unterscheidet sich von dem anderer langlebender sozialer Primaten. Phänotypische Plastizität ist die Fähigkeit eines Organismus sich in Form, Zustand, Aktivitätsrate oder Verhalten an unterschiedliche Umweltbedingungen anzupassen (West-Eberhard 2003). Beim Menschen wird diese Plastizität u.a. sichtbar, wenn sich anthropometrisch bestimmbare Merkmale im Vergleich von Populationen in relativ kurzer Zeit ändern. Der Schwerpunkt der vorliegenden Arbeit ist es, altersspezifische Änderung von Körpermaßen (Skelettbreiten, Körperendhöhe und Fettverteilungsmuster) aufeinanderfolgender Populationen in Abhängigkeit von neuen Umweltparametern zu vergleichen. Dem liegen ca. 75 000 anthropo-metrische Datensätzen von Kindern und Jugendlichen seit 1980 bis heute und historische Datensätze aus der Literatur zugrunde. Aufgrund verringerter alltäglicher Bewegung haben heutige 6-18-Jährige geringere Werte der Becken- und der Ellenbogenbreiten. Die beobachtete Zunahme der Körperhöhe lässt sich entgegen früherer Erklärungen (Einfluss von Ernährung, guter Lebensbedingungen und Genetik) durch Hierarchien in sozialen Netzwerken menschlicher Gesellschaften erklären. Eine Verschiebung zu einem eher weiblichen Fettverteilungsmuster bei Jungen und Mädchen findet sich parallel zur Zunahme von Chemikalien in unserer Umwelt, die das Hormonsystem beeinflussen können. Die beschriebene Plastizität des Phänotyps findet im Rahmen des genetisch manifestierten Wachstumsmusters bei Kindern und Jugendlichen statt. Epigenetische Einflüsse können nicht ausgeschlossen werden, sind aber an Körpermaßdaten per se nicht bestimmbar. Die Veränderung der analysierten Körpermaße unterstreicht, dass der Phänotyp des Menschen sich an veränderte Umweltbedingungen sehr plastisch anpassen kann. Wegen der langsamen Generationenfolge und Entwicklung des Menschen sind derartige eigentlich kurzfristige Veränderungen nur über einen Zeitraum von mindestens 5-30 Jahren zu beobachten. KW - plasticity KW - skeletal breadth measurement KW - Fat Patterning KW - secular trend KW - body height Y1 - 2018 ER -