Focal Individuals Research Articles

Exploring How a Generalist Pathogen and Within-Host Priority Effects Alter the Risk of Being Infected by a Specialist Pathogen.

AbstractIn multihost-multipathogen communities, a focal host's risk of being infected by a particular pathogen can be influenced by the presence of other host and pathogen species. We explore how indirect interactions between pathogens at the within-host level (through coinfecting the same individual) and the between-host level (through altered susceptible host densities) affect the focal host's risk of infection. We use an SI-type epidemiological model of two host species and two environmentally transmitted pathogens where one pathogen is a specialist on the focal host and the other pathogen is a generalist. We show that monotonic, unimodal, and U-shaped relationships between the specialist and generalist infectious propagule densities (proxies of the focal host's risk of infection) are driven by the way within-host priority effects alter the production of specialist infectious propagules by infected focal host individuals. Interestingly, within-host priority effects can also lead to overcompensation in density wherein increased infected host mortality results in greater specialist infectious propagule density. We interpret these results in terms of how the focal host's risk of being infected by a specialist pathogen is affected by the presence of a generalist pathogen, its alternative host, and within-host priority effects.

Cascading indirect genetic effects in a clonal vertebrate.

Understanding how individual differences arise and how their effects propagate through groups are fundamental issues in biology. Individual differences can arise from indirect genetic effects (IGE): genetically based variation in the conspecifics with which an individual interacts. Using a clonal species, the Amazon molly (Poecilia formosa), we test the hypothesis that IGE can propagate to influence phenotypes of the individuals that do not experience them firsthand. We tested this by exposing genetically identical Amazon mollies to conspecific social partners of different clonal lineages, and then moving these focal individuals to new social groups in which they were the only member to have experienced the IGE. We found that genetically different social environments resulted in the focal animals experiencing different levels of aggression, and that these IGE carried over into new social groups to influence the behaviour of naive individuals. These data reveal that IGE can cascade beyond the individuals that experience them. Opportunity for cascading IGE is ubiquitous, especially in species with long-distance dispersal or fission-fusion group dynamics. Cascades could amplify (or mitigate) the effects of IGE on trait variation and on evolutionary trajectories. Expansion of the IGE framework to include cascading and other types of carry-over effects will therefore improve understanding of individual variation and social evolution and allow more accurate prediction of population response to changing environments.

A comparison of foraging‐range sizes, flight distances and foraging habitat preferences in urban and rural House Sparrow (Passer domesticus) populations

Lack of food for nestlings is a crucial factor influencing population size and dynamics in birds. It is one of the most cited reasons for recent House Sparrow Passer domesticus population declines in cities and rural settlements. However, a detailed comparative study of habitat use by parents delivering food to offspring in different environments is still missing. To obtain the most detailed information on fine‐scale foraging habitat selection, foraging‐range size, flight distance and foraging duration in typical Central European urban and rural environments, we conducted systematic observations of colour‐ringed focal individuals feeding their offspring. We found that urban House Sparrows had larger foraging‐range sizes and longer foraging distances than rural birds. Additionally, some preferred habitats, such as ruderal and woody vegetation, occurred less frequently in the urban area and consequently increased flight distance to key sources of invertebrate prey. In both environments, the most selected habitats – bin storage areas and poultry holdings – offered a stable and rich but probably lower quality ‘fast food’ source. Birds were willing to fly a longer distance to forage at bin storage areas, tall ruderal vegetation and poultry holdings. Our findings imply that natural food sources in the urban environment are scarce and scattered. Due to the improvement of socio‐economic status associated with better handling of waste products in both urban and rural environments, sprawl of highly urbanized areas and intensification of farming, important foraging habitats have thus decreased. We highlight the importance of maintaining suitable small‐ and medium‐scale farms in rural areas and suggest improvements in the management of green spaces in all types of human settlements that may support House Sparrow populations.

Individualism versus collective movement during travel

Collective movement may emerge if coordinating one’s movement with others produces a greater benefit to oneself than can be achieved alone. Experimentally, the capacity to manoeuvre simulated groups in the wild could enable powerful tests of the impact of collective movement on individual decisions. Yet such experiments are currently lacking due to the inherent difficulty of controlling whole collectives. Here we used a novel technique of experimentally simulating the movement of collectives of social hermit crabs (Coenobita compressus) in the wild. Using large architectural arrays of shells dragged across the beach, we generated synchronous collective movement and systematically varied the simulated collective’s travel direction as well as the context (i.e., danger level). With drone video from above, we then tested whether focal individuals were biased in their movement by the collective. We found that, despite considerable engagement with the collective, individuals’ direction was not significantly biased. Instead, individuals expressed substantial variability across all stimulus directions and contexts. Notably, individuals typically achieved shorter displacements in the presence of the collective versus in the presence of the control stimulus, suggesting an impact of traffic. The absence of a directional bias in individual movement due to the collective suggests that social hermit crabs are individualists, which move with a high level of opportunistic independence, likely thanks to the personal architecture and armour they carry in the form of a protective shell. Future studies can manipulate this level of armour to test its role in autonomy of movement, including the consequences of shell architecture for social decisions. Our novel experimental approach can be used to ask many further questions about how and why collective and individual movement interact.

Capturing indirect genetic effects on phenotypic variability: Competition meets canalization.

Phenotypic variability of a genotype is relevant both in natural and domestic populations. In the past two decades, variability has been studied as a heritable quantitative genetic trait in its own right, often referred to as inherited variability or environmental canalization. So far, studies on inherited variability have only considered genetic effects of the focal individual, that is, direct genetic effects on inherited variability. Observations from aquaculture populations and some plants, however, suggest that an additional source of genetic variation in inherited variability may be generated through competition. Social interactions, such as competition, are often a source of Indirect Genetic Effects (IGE). An IGE is a heritable effect of an individual on the trait value of another individual. IGEs may substantially affect heritable variation underlying the trait, and the direction and magnitude of response to selection. To understand the contribution of IGEs to evolution of environmental canalization in natural populations, and to exploit such inherited variability in animal and plant breeding, we need statistical models to capture this effect. To our knowledge, it is unknown to what extent the current statistical models commonly used for IGE and inherited variability capture the effect of competition on inherited variability. Here, we investigate the potential of current statistical models for inherited variability and trait values, to capture the direct and indirect genetic effects of competition on variability. Our results show that a direct model of inherited variability almost entirely captures the genetic sensitivity of individuals to competition, whereas an indirect model of inherited variability captures the cooperative genetic effects of individuals on their partners. Models for trait levels, however, capture only a small part of the genetic effects of competition. The estimation of direct and indirect genetic effects of competition, therefore, is possible with models for inherited variability but may require a two‐step analysis.

How anger works

Anger appears to be a neurocognitive adaptation designed to bargain for better treatment, and is primarily triggered by indications that another individual values the focal individual insufficiently. Once activated, anger orchestrates cognitive, physiological, and behavioral responses geared to incentivize the target individual to place more weight on the welfare of the focal individual. Here, we evaluate the hypothesis that anger works by matching in intensity the various outputs it controls to the magnitude of the current input—the precise degree to which the target appears to undervalue the focal individual. By magnitude-matching outputs to inputs, the anger system balances the competing demands of effectiveness and economy and avoids the dual errors of excessive diffidence and excessive belligerence in bargaining. To test this hypothesis, we measured the degree to which audiences devalue each of 39 negative traits in others, and how individuals would react, for each of those 39 traits, if someone slandered them as possessing those traits. We observed the hypothesized magnitude-matchings. The intensities of the anger feeling and of various motivations of anger (telling the offender to stop, insulting the offender, physically attacking the offender, stopping talking to the offender, and denying help to the offender) vary in proportion to: (i) one another, and (ii) the reputational cost that the slanderer imposes on the slandered (proxied by audience devaluation). These patterns of magnitude-matching were observed both within and between the United States and India. These quantitative findings echo laypeople's folk understanding of anger and suggest that there are cross-cultural regularities in the functional logic and content of anger.

Low heritability and high phenotypic plasticity of salivary cortisol in response to environmental heterogeneity in a wild pinniped.

Individuals are unique in how they interact with and respond to their environment. Correspondingly, unpredictable challenges or environmental stressors often produce an individualized response of the hypothalamic‐pituitary‐adrenal (HPA) axis and its downstream effector cortisol. We used a fully crossed, repeated measures design to investigate the factors shaping individual variation in baseline cortisol in Antarctic fur seal pups and their mothers. Saliva samples were collected from focal individuals at two breeding colonies, one with low and the other with high density, during two consecutive years of contrasting food availability. Mothers and pups were sampled concurrently at birth and shortly before weaning, while pups were additionally sampled every 20 days. We found that heritability was low for baseline cortisol, while within‐individual repeatability and among‐individual variability were high. A substantial proportion of the variation in baseline cortisol could be explained in pups and mothers by a combination of intrinsic and extrinsic factors including sex, weight, day, season, and colony of birth. Our findings provide detailed insights into the individualization of endocrine phenotypes and their genetic and environmental drivers in a wild pinniped. Furthermore, the strong associations between cortisol and life history traits that we report in fur seals could have important implications for understanding the population dynamics of species impacted by environmental change.

Preliminary insights into associations between C-reactive protein and social network dynamics

Recent social psychoneuroimmunology models suggest bidirectional associations between social experiences and the immune system. This work posits that social relationships and networks may influence the functioning of the immune system, but we know little about the role that the immune system plays in how social networks are created and maintained. We examine how salivary C-reactive protein (CRP), as an inflammatory protein, is associated with making new and keeping existing friendship and conflicted relationships among young adult members of a social group. Participants (n = 37; 67.6% female; M age = 18.18 years, 56.81% white/non-Hispanic) provided nominations of friends and individuals with whom they have conflict at wave 1 and two months later at wave 2. At wave 1, in a group setting, participants donated saliva, later assayed for CRP. Stochastic actor-based models revealed that CRP levels were negatively associated with keeping existing friends and positively associated with developing new friendships. We also found that CRP levels were negatively associated with creating new conflicted relationships and predicted an increased likelihood that group members continue conflicted relationships with the focal individual. These preliminary results support the premises of recent social psychoneuroimmunology models by suggesting that inflammation can also serve as a signal to seek new supportive relationships such as friendships and avoid creating new relationships characterized by threat and/or conflict. Findings provide new insights into the theorized function of the immune system for social approach and withdrawal patterns through which our social connections are constructed.

The strength and direction of local (mal)adaptation depends on neighbour density and the environment

Abstract Populations are embedded in communities, but despite their potential to affect individual fitness, it is unknown whether and how species interactions evolve in communities. Evolutionary outcomes are likely more complex in natural communities because (a) the evolution of interactions may not be evenly distributed among all community members and (b) coevolution is conditional on the environmental conditions within which interactions are playing out. To test the evolution of interaction strengths in natural communities, we performed two common garden experiments in grassland communities in Northern California. In each garden, we transplanted individuals of four populations (one local, three foreign) of an annual invasive grass Bromus hordeaceus into natural communities, characterized the interaction neighbourhood around each focal individual, and quantified individual fitness. This method allowed us to fit multispecies competition models to fitness data, estimating interaction strengths between focal B. hordeaceus populations and each of seven species that were common in the interaction neighbourhoods, in each garden. We found that interaction strengths significantly differed among local and foreign source populations, but the direction and magnitude of evolution differed among common gardens and among neighbour species—in neither garden were interactions experienced more strongly by foreign populations compared to local populations. The fitness of local populations (relative to foreign populations) decreased when neighbours were removed, strongly enough in one garden to cause strong local maladaptation, and the local population did not perform the best in either garden. Synthesis. Together, our results demonstrate how species interactions evolve to determine fitness in ecological communities, providing a richer view of adaptation in natural systems. In our study, this richness included the unique challenges populations face in nature: uneven abundances and a diffuseness of species interactions, nonlinear density effects on fitness, and evidence of (mal)adaptation that is conditional on local conditions. We conclude by hypothesizing the causes and consequences of challenges to adaptation and how they help identify priority areas for the field.

No Impact of Biocontrol Agent's Predation Cues on Development Time or Size of Surviving Aedes albopictus under Optimal Nutritional Availability.

Simple SummaryAedes albopictus is a highly invasive species of mosquito that can infect humans with chikungunya, dengue, yellow fever, and Zika. Within the next few decades, this mosquito species is predicted to invade South East England. Cyclopoid copepods are small crustaceans that have previously been used as biocontrol agents due to their high efficiency at killing small early instar mosquito larvae. We assessed the effect of Megacyclops viridis, a copepod species local to South East England, on the survival and traits of mosquito larvae exposed to these predators during the larger late instar stage. Our experiment was designed to measure the impact of copepod predation on both the development time and adult body size of Ae. albopictus. These traits can shape mosquito population dynamics and disease transmission. While we found that copepod attacks cause a small increase in late instar mortality, our methods did not detect a significant difference in either development time or size between the predator and control treatments. The lack of a strong sublethal effect on these traits supports the use of M. viridis copepods as biocontrol agents against Ae. albopictus in the UK. This information may be useful for guiding public health measures that aim to prevent outbreaks of mosquito-borne disease.Cyclopoid copepods have been applied successfully to limit populations of highly invasive Aedes albopictus mosquitoes that can transmit diseases of public health importance. However, there is concern that changes in certain mosquito traits, induced by exposure to copepod predation, might increase the risk of disease transmission. In this study, third instar Ae. albopictus larvae (focal individuals) were exposed to Megacyclops viridis predator cues associated with both the consumption of newly hatched mosquito larvae and attacks on focal individuals. The number of newly hatched larvae surrounding each focal larva was held constant to control for density effects on size, and the focal individual’s day of pupation and wing length were recorded for each replicate. Exposing late instar Ae. albopictus to predation decreased their chances of surviving to adulthood, and three focal larvae that died in the predator treatment showed signs of melanisation, indicative of wounding. Among surviving focal Ae. albopictus, no significant difference in either pupation day or wing length was observed due to copepod predation. The absence of significant sublethal impacts from M. viridis copepod predation on surviving later stage larvae in this analysis supports the use of M. viridis as a biocontrol agent against Ae. albopictus.

Spatial patterns in neighbourhood effects on woody plant selection and bark stripping by deer in a lowland alluvial forest

AbstractQuestionsUngulate herbivory and its impact on one plant species may be driven by other plants in the neighbourhood. Although such neighbourhood effects have long been recognized, there is limited understanding of how spatial variation in these effects relates to local plant density and distances between plants. Our goal was to examine if the density of or distance to conspecific and heterospecific neighbouring woody individuals produces neighbourhood effects on bark stripping by deer, and how these effects differ in spatial scale and type (reduce/increase herbivory).LocationLowland old‐growth forest, Czech Republic.MethodsWoody individuals were assessed for evidence of bark stripping and the level of damage done by deer in a square 4‐ha plot, mapping all woody stems ≥1 cm diameter at breast height. The spatial distribution of stripping was used to examine neighbourhood effects using spatial point pattern methods.ResultsThe density and distance to neighbours and species identity of focal and neighbouring individuals contributed to a large spatial variation in neighbourhood effects (up to distances of 2–30 m from neighbours). Neighbourhood effects arose mainly from the interactions between neighbouring shrub species and all tree species, and interactions between individual species pairs. Neighbourhood effects more often increased than reduced the stripping of focal individuals. The stripping of Ulmus laevis, Acer campestre and Crataegus laevigata increased near conspecifics, while the stripping of all tree species was more likely near Ulmus laevis, Fraxinus angustifolia and shrubs. Heterospecific tree species were less susceptible to stripping near Tilia cordata and especially Carpinus betulus.ConclusionOur study provides new insight into neighbourhood effects by showing how and at which spatial scales woody plant interactions modify deer herbivory. We advocate considering the life stage and relevant plant traits with multivariate spatial methods in order to elucidate the role of neighbourhood effects in complex plant communities.

Non-additive biotic interactions improve predictions of tropical tree growth and impact community size structure.

Growth in individual size or biomass is a key demographic component in population models, with wide-ranging applications from quantifying species performance across abiotic or biotic conditions to assessing landscape-level dynamics under global change. In forest ecology, the responses of tree growth to biotic interactions are widely held to be crucial for understanding forest diversity, function, and structure. To date, most studies on plant-plant interactions only examine the additive competitive or facilitative interactions between species pairs; however, there is increasing evidence of non-additive, higher-order interactions (HOIs) impacting species demographic rates. When HOIs are present, the dynamics of a multispecies community cannot be fully understood or accurately predicted solely from pairwise outcomes because of how additional species "interfere" with the direct, pairwise interactions. Such HOIs should be particularly prevalent when species show non-linear functional responses to resource availability and resource-acquisition traits themselves are density dependent. With this in mind, we used data from a tropical secondary forest-a system that fulfills both of these conditions-to build an ontogenetic diameter growth model for individuals across 10 woody-plant species. We allowed both direct and indirect interactions within communities to influence the species-specific growth parameters in a generalized Lotka-Volterra model. Specifically, indirect interactions entered the model as higher-order quadratic terms, i.e., non-additive effects of conspecific and heterospecific neighbor size on the focal individual's growth. For the whole community and for four out of 10 focal species, the model that included HOIs had more statistical support than the model that included only direct interactions, despite the former containing a far greater number of parameters. HOIs had comparable effect sizes to direct interactions, and tended to further reduce the diameter growth rates of most species beyond what direct interactions had already reduced. In a simulation of successional stand dynamics, the inclusion of HOIs led to rank swaps in species' diameter hierarchies, even when community-level size distributions remained qualitatively similar. Our study highlights the implications, and discusses possible mechanisms, of non-additive density dependence in highly diverse and light-competitive tropical forests.

Phenotypic Assortment Changes the Landscape of Selection.

Social interactions with conspecifics can dramatically affect an individual's fitness. The positive or negative consequences of interacting with social partners typically depend on the value of traits that they express. These pathways of social selection connect the traits and genes expressed in some individuals to the fitness realized by others, thereby altering the total phenotypic selection on and evolutionary response of traits across the multivariate phenotype. The downstream effects of social selection are mediated by the patterns of phenotypic assortment between focal individuals and their social partners (the interactant covariance, Cij', or the multivariate form, CI). Depending on the sign and magnitude of the interactant covariance, the direction of social selection can be reinforced, reversed, or erased. We report estimates of Cij' from a variety of studies of forked fungus beetles to address the largely unexplored questions of consistency and plasticity of phenotypic assortment in natural populations. We found that phenotypic assortment of male beetles based on body size or horn length was highly variable among subpopulations, but that those differences also were broadly consistent from year to year. At the same time, the strength and direction of Cij' changed quickly in response to experimental changes in resource distribution and social properties of populations. Generally, interactant covariances were more negative in contexts in which the number of social interactions was greater in both field and experimental situations. These results suggest that patterns of phenotypic assortment could be important contributors to variability in multilevel selection through their mediation of social selection gradients.

Observer effects in a remote population of large-headed capuchins, Sapajus macrocephalus

Human observers often are present when researchers record animal behavior, which can create observer effects. These effects are rarely explicitly investigated, often due to the assumption that the study animal is habituated to or unaffected by a human’s presence. We investigated the effect of human pressure gradients on a remote population of large-headed capuchins, Sapajus macrocephalus, looking specifically at the effects of number of observers, distance to observers, and distance to the research base. We conducted this study over 4 months in the Pacaya-Samiria Nature Reserve, Peru, and collected 199 two-minute focal samples of capuchin behavior. We found that capuchin monkeys fed less when human observers were closer to the focal individual, when more observers were present, and when capuchins were closer to the research base. We found no other consistent differences in capuchin monkey behavior across the measured human pressure gradients, although capuchins directed a high proportion of their vigilance toward humans (29% in adults and 47% in infants). Our results support the hypothesis that human pressure gradients influence animal behavior. Given the proportion of human directed vigilance, we recommend that all studies that use human observers to record animal behavior consider human-directed vigilance, record the number of observers, as well as the observer-focal animal distance, to check for these effects.

Metabolic phenotype mediates the outcome of competitive interactions in a response-surface field experiment.

Competition and metabolism should be linked. Intraspecific variation in metabolic rates and, hence, resource demands covary with competitive ability. The effects of metabolism on conspecific interactions, however, have mostly been studied under laboratory conditions. We used a trait‐specific response‐surface design to test for the effects of metabolism on pairwise interactions of the marine colonial invertebrate, Bugula neritina in the field. Specifically, we compared the performance (survival, growth, and reproduction) of focal individuals, both in the presence and absence of a neighbor colony, both of which had their metabolic phenotype characterized. Survival of focal colonies depended on the metabolic phenotype of the neighboring individual, and on the combination of both the focal and neighbor colony metabolic phenotypes that were present. Surprisingly, we found pervasive effects of neighbor metabolic phenotypes on focal colony growth and reproduction, although the sign and strength of these effects showed strong microenvironmental variability. Overall, we find that the metabolic phenotype changes the strength of competitive interactions, but these effects are highly contingent on local conditions. We suggest future studies explore how variation in metabolic rate affects organisms beyond the focal organism alone, particularly under field conditions.

Relational Demography: A Three-decade Literature Review

Relational demography focuses on the influence of differences or similarities in demographic characteristics between individuals and others (such as between superiors and subordinates, between individuals and other members of the team) that constitute a mutual relationship in the workplace, on the attitudes and behaviors of the focal individual. As women, minorities and other groups that are traditionally marginalized in the workplace occupy more and more central positions, and the new generation of employees, professionals, and highly-educated people begin to play more and more important roles in the organization, the diversity of employees in the organization is increasing. However, as an important branch of diversification research, relational demography has been ignored by Chinese scholars. This neglect has caused adverse effects both in practice and in theory. In view of this, this study divides the research on relational demography into different stages, draws on the relevant theoretical framework, and systematically organizes the development of the research on relational demography in the past 30 years.Firstly, by reviewing the research on relational demography in the early stage (1989-1999), this article summarizes these studies in terms of concepts, measurements, theories, and boundary conditions, as well as shortcomings. Scholars mainly use the similar attraction framework and social identity theory to explain the influence of relational demography on the outcome, and use Euclidean distance and interaction terms to measure relational demography. There are three main flaws in the early stage: First, the five types of relational demography, such as gender, age, education level, tenure, and race, cannot cover the rich content of demographic characteristics. Second, there is a lack of research on further categorizing these characteristics. Third, the measurements are diverse and inconsistent, making it difficult to dialogue and integrate research conclusions.Secondly, this article summarizes the progress made in the research on relational demography in the past two decades (2000-present), and analyzes how recent research has made up for the shortcomings of the early-stage research. First, the dimension of relational demography is constantly enriched, from shallow to deep demographic characteristics and from dual to ternary relationship, and taking into account the similarity of family background. Second, scholars try to identify the similarities between different relational demography, and then categorize and analyze them. Third, this study integrates different measurements and theories. To use different measurements reasonably and effectively, scholars systematically compare four measurements, analyze the defects of each measurement, and point out their application scope.Finally, this article specifically discusses the future direction of the research on relational demography in terms of concepts and theories, and looks forward to the main development direction in the Chinese context. First, the theory of expanding relational demography will remain the most fruitful direction. Second, the boundary conditions of relational demography have greater possibilities for expansion. Third, the time is introduced into the study of relational demography, which is one of the waves that cannot be ignored in the research of organizational behavior. Fourth, the special demographic phenomenon in the Chinese context provides an opportunity to expand the conceptual extension of the study of relational demography. Fifth, the Chinese context should be the frontier for testing and developing theories related to relational demography.

Camera traps with white flash are a minimally invasive method for long‐term bat monitoring

AbstractCamera traps are an increasingly popular survey tool for ecological research and biodiversity conservation, but studies investigating their impact on focal individuals have been limited to only a few mammal species. In this context, echolocating bats are particularly interesting as they rely less on vision for navigation, yet show a strong negative reaction to constant illumination. At hibernacula, camera traps with white flash could offer an efficient alternative method for monitoring threatened bat species, but the potential negative impact of white flash on bat behavior is unknown. Here, we investigate the effect of camera traps emitting white flash at four hibernation sites fitted with infrared light barriers, infrared video cameras, and acoustic recorders over 16 weeks. At each site, the flash was turned off every second week. We quantified whether flash affected (1) nightly bat passes using generalized linear mixed models, (2) flight direction of entering bats using permutational multivariate analyses, and (3) latency of the first echolocation call after the camera trap trigger using randomization tests. Additionally, we quantified and corrected for the potential impact of confounding factors, such as weather and social interactions. Overall, white flash did not influence short‐ or long‐term bat activity, flight direction or echolocation behavior. A decrease in nightly bat activity was observed with an increasing proportion of hours with rain. Moreover, flight direction was affected by the presence of other bats, likely due to chasing and avoidance behavior. Our findings highlight the potential of camera traps with white flash triggered by infrared light barriers as a minimally invasive method for long‐term bat population monitoring and observation of species‐specific phenology. Such automated monitoring technologies can improve our understanding of long‐term population dynamics across a wide range of spatial‐temporal scales and taxa and consequently, contribute to data‐driven wildlife conservation and management.

Child’s Gender, Young Fathers’ Crime, and Spillover Effects in Criminal Behavior

Men who father their first child at a very young age are convicted of significantly fewer crimes in the first years after birth if the child is a son rather than a daughter. This leads to behavioral spillovers that reduce criminal convictions among other young men living in the same neighborhood, with the resulting crime multipliers affecting peers’ crime even after the primary impact on the focal individual has dissipated. Through social multipliers, prevention policies that target potential criminals at an early stage, therefore, lead to larger reductions in the cost of crime than suggested by primary effects alone.

The Evolution of Social Behaviour

The Evolution of Social Behaviour

A dyadic approach toward the interpersonal consequences of time pressure.

Although time pressure can decisively shape employees' behavior, little remains known about the consequences associated with differing perceptions of time pressure between cooperating individuals. Hence, this investigation uses two experimental studies (across different cultural contexts) to examine the joint role of a focal individual's (i.e., an actor's) and a dyadic interaction partner's time pressure perceptions for the actor's behavior toward the partner. Results demonstrated that actors' time pressure perceptions were positively related to their time-oriented behavior (i.e., pacing and synchronizing joint activities). In Study 1 (but not Study 2), the partner's time pressure moderated this association, such that the linkage between an actor's time pressure and time-oriented behavior was more pronounced when the partner experienced lower (rather than higher) time pressure. Furthermore, across both studies, the partner's time pressure perceptions moderated the linkage between an actor's time pressure and relationship-oriented behavior (i.e., being friendly and considerate). This linkage was positive when the partner experienced high time pressure, but nonsignificant (Study 1) or even negative (Study 2) when the partner experienced low time pressure. Together, these findings advance new insights into the consequences of time pressure in cooperating dyads, illustrating that conflicting time pressure perceptions may critically influence individuals' interpersonal behavior. (PsycInfo Database Record (c) 2021 APA, all rights reserved).