Child temperament and parental personality: continuity and transactional change

Studying the continuity and underlying mechanisms of temperament change from early childhood through adulthood is clinically and theoretically relevant. Knowledge of the continuity and change of temperament from infancy onwards, especially as perceived by both parents is, however, still scanty. Only in recent years have researchers become aware that personality, long considered as stable in adulthood, may also change. Further, studies that focus on the transactional change of child temperament and parental personality also seem to be lacking, as are studies focusing on transactions between child temperament and more transient parental characteristics, like parental stress. Therefore, this longitudinal study examined the degree of continuity of temperament over five years from the infant s age of six months to the child s age of five and a half years, as perceived by both biological parents, and also investigated the bidirectional effects between child temperament and parents personality traits and overall stress experienced during that time. First, moderate to high levels of continuity of temperament from infancy to middle childhood were shown, depicting the developmental links between affectively positive and well-adjusted temperament characteristics, and between characteristics of early and later negative affectivity. The continuity of temperament was quantitatively and qualitatively similar in both parents ratings. The findings also demonstrate that infant and childhood temperament characteristics cluster to form stable temperament types that resemble personality types shown in child and adult personality studies. Second, the parental personality traits of extraversion and neuroticism were shown to be highly stable over five years, but evidence of change in relation to parents views of their child s temperament was also shown: an infant s higher positive affectivity predicted an increase in parental extraversion, while the infant s higher activity level predicted a decrease in parental neuroticism over five years. Furthermore, initially higher parental extraversion predicted higher ratings of the child s effortful control, while initially higher parental neuroticism predicted the child s higher negative affectivity. In terms of changes in parental stress, the infant s higher activity level predicted a decrease in maternal overall stress, while initially higher maternal stress predicted a higher level of child negative affectivity in middle childhood. Together, the results demonstrate that the mother- and father-rated temperament of the child shows continuity during the early years of life, but also support the view that the development of these characteristics is sensitive to important contextual factors such as parental personality and overall stress. While parental personality and experienced stress were shown to have an effect on the child s developing temperament, the reverse was also true: the parents own personality traits and perceived stress seemed to be highly stable, but also susceptible to their experiences of their child s temperament.

Individuals on the Move : Body Condition Dependent Dispersal and Quasi-Local Competition in Metapopulations

Individual movement is very versatile and inevitable in ecology. In this thesis, I investigate two kinds of movement body condition dependent dispersal and small-range foraging movements resulting in quasi-local competition and their causes and consequences on the individual, population and metapopulation level. Body condition dependent dispersal is a widely evident but barely understood phenomenon. In nature, diverse relationships between body condition and dispersal are observed. I develop the first models that study the evolution of dispersal strategies that depend on individual body condition. In a patchy environment where patches differ in environmental conditions, individuals born in rich (e.g. nutritious) patches are on average stronger than their conspecifics that are born in poorer patches. Body condition (strength) determines competitive ability such that stronger individuals win competition with higher probability than weak individuals. Individuals compete for patches such that kin competition selects for dispersal. I determine the evolutionarily stable strategy (ESS) for different ecological scenarios. My models offer explanations for both dispersal of strong individuals and dispersal of weak individuals. Moreover, I find that within-family dispersal behaviour is not always reflected on the population level. This supports the fact that no consistent pattern is detected in data on body condition dependent dispersal. It also encourages the refining of empirical investigations. Quasi-local competition defines interactions between adjacent populations where one population negatively affects the growth of the other population. I model a metapopulation in a homogeneous environment where adults of different subpopulations compete for resources by spending part of their foraging time in the neighbouring patches, while their juveniles only feed on the resource in their natal patch. I show that spatial patterns (different population densities in the patches) are stable only if one age class depletes the resource very much but mainly the other age group depends on it.

Analysing local algorithms in location-aware quasi-unit-disk graphs

A local algorithm with local horizon r is a distributed algorithm that runs in r synchronous communication rounds; here r is a constant that does not depend on the size of the network. As a consequence, the output of a node in a local algorithm only depends on the input within r hops from the node. We give tight bounds on the local horizon for a class of local algorithms for combinatorial problems on unit-disk graphs (UDGs). Most of our bounds are due to a refined analysis of existing approaches, while others are obtained by suggesting new algorithms. The algorithms we consider are based on network decompositions guided by a rectangular tiling of the plane. The algorithms are applied to matching, independent set, graph colouring, vertex cover, and dominating set. We also study local algorithms on quasi-UDGs, which are a popular generalisation of UDGs, aimed at more realistic modelling of communication between the network nodes. Analysing the local algorithms on quasi-UDGs allows one to assume that the nodes know their coordinates only approximately, up to an additive error. Despite the localisation error, the quality of the solution to problems on quasi-UDGs remains the same as for the case of UDGs with perfect location awareness. We analyse the increase in the local horizon that comes along with moving from UDGs to quasi-UDGs.

Fuzzy Coherence: Making Sense of Continuity in Hypertext Narratives

Hypertexts are digital texts characterized by interactive hyperlinking and a fragmented textual organization. Increasingly prominent since the early 1990s, hypertexts have become a common text type both on the Internet and in a variety of other digital contexts. Although studied widely in disciplines like hypertext theory and media studies, formal linguistic approaches to hypertext continue to be relatively rare. This study examines coherence negotiation in hypertext with particularly reference to hypertext fiction. Coherence, or the quality of making sense, is a fundamental property of textness. Proceeding from the premise that coherence is a subjectively evaluated property rather than an objective quality arising directly from textual cues, the study focuses on the processes through which readers interact with hyperlinks and negotiate continuity between hypertextual fragments. The study begins with a typological discussion of textuality and an overview of the historical and technological precedents of modern hypertexts. Then, making use of text linguistic, discourse analytical, pragmatic, and narratological approaches to textual coherence, the study takes established models developed for analyzing and describing conventional texts, and examines their applicability to hypertext. Primary data derived from a collection of hyperfictions is used throughout to illustrate the mechanisms in practice. Hypertextual coherence negotiation is shown to require the ability to cognitively operate between local and global coherence by means of processing lexical cohesion, discourse topical continuities, inferences and implications, and shifting cognitive frames. The main conclusion of the study is that the style of reading required by hypertextuality fosters a new paradigm of coherence. Defined as fuzzy coherence, this new approach to textual sensemaking is predicated on an acceptance of the coherence challenges readers experience when the act of reading comes to involve repeated encounters with referentially imprecise hyperlinks and discourse topical shifts. A practical application of fuzzy coherence is shown to be in effect in the way coherence is actively manipulated in hypertext narratives.