Putting like a pro: the role of positive contagion in golf performance and perception

Many amateur athletes believe that using a professional athlete's equipment can improve their performance. Such equipment can be said to be affected with positive contagion, which refers to the belief of transference of beneficial properties between animate persons/objects to previously neutral objects. In this experiment, positive contagion was induced by telling participants in one group that a putter previously belonged to a professional golfer. The effect of positive contagion was examined for perception and performance in a golf putting task. Individuals who believed they were using the professional golfer's putter perceived the size of the golf hole to be larger than golfers without such a belief and also had better performance, sinking more putts. These results provide empirical support for anecdotes, which allege that using objects with positive contagion can improve performance, and further suggest perception can be modulated by positive contagion.     

In Bonobos Yawn Contagion Is Higher among Kin and Friends

In humans, the distribution of yawn contagion is shaped by social closeness with strongly bonded pairs showing higher levels of contagion than weakly bonded pairs. This ethological finding led the authors to hypothesize that the phenomenon of yawn contagion may be the result of certain empathic abilities, although in their most basal form. Here, for the first time, we show the capacity of bonobos (Pan paniscus) to respond to yawns of conspecifics. Bonobos spontaneously yawned more frequently during resting/relaxing compared to social tension periods. The results show that yawn contagion was context independent suggesting that the probability of yawning after observing others'' yawns is not affected by the propensity to engage in spontaneous yawns. As it occurs in humans, in bonobos the yawing response mostly occurred within the first minute after the perception of the stimulus. Finally, via a Linear Mixed Model we tested the effect of different variables (e.g., sex, rank, relationship quality) on yawn contagion, which increased when subjects were strongly bonded and when the triggering subject was a female. The importance of social bonding in shaping yawn contagion in bonobos, as it occurs in humans, is consistent with the hypothesis that empathy may play a role in the modulation of this phenomenon in both species. The higher frequency of yawn contagion in presence of a female as a triggering subject supports the hypothesis that adult females not only represent the relational and decisional nucleus of the bonobo society, but also that they play a key role in affecting the emotional states of others.     

Male yawning is more contagious than female yawning among chimpanzees (Pan troglodytes)

Yawn contagion is not restricted to humans and has also been reported for several non-human animal species, including chimpanzees (Pan troglodytes). Contagious yawning may lead to synchronisation of behaviour. However, the function of contagious yawning is relatively understudied. In this study, we investigated the function of contagious yawning by focusing on two types of signal providers: close social associates and leaders. We provided a captive chimpanzee colony with videos of all individuals of their own group that were either yawning, or at rest. Consistent with other studies, we demonstrated that yawning is contagious for chimpanzees, yet we did not find any effect of relationship quality on yawn contagion. However, we show that yawn contagion is significantly higher when the video model is a yawning male than when the video model was a yawning female, and that this effect is most apparent among males. As males are dominant in chimpanzee societies, male signals may be more relevant to the rest of the group than female signals. Moreover, since chimpanzees form male-bonded societies, male signals are especially relevant for other males. Therefore, we suggest that the sex-differences of yawning contagion among chimpanzees reflect the function of yawning in the synchronisation of behaviour.     

Salience of emotional displays of danger and contagion in faces is enhanced when progesterone levels are raised

Findings from previous studies of hormone-mediated behavior in women suggest that raised progesterone level increases the probability of behaviors that will reduce the likelihood of disruption to fetal development during pregnancy (e.g. increased avoidance of sources of contagion). Here, we tested women's (N=52) sensitivity to potential cues to nearby sources of contagion (disgusted facial expressions with averted gaze) and nearby physical threat (fearful facial expressions with averted gaze) at two points in the menstrual cycle differing in progesterone level. Women demonstrated a greater tendency to perceive fearful and disgusted expressions with averted gaze as more intense than those with direct gaze when their progesterone level was relatively high. By contrast, change in progesterone level was not associated with any change in perceptions of happy expressions with direct and averted gaze, indicating that our findings for disgusted and fearful expressions were not due to a general response bias. Collectively, our findings suggest women are more sensitive to facial cues signalling nearby contagion and physical threat when raised progesterone level prepares the body for pregnancy.     

Socio-ecological contagion in Veganville

In order to meet the 2015 Paris Agreement for 1.5 °C global warming, per capita emissions need to come down to 2.9 tonnes by 2030. Food systems are known to be a significant source of an individual's carbon footprint and demand attention in sustainability management. The objective of this research is to conceptualise and define an intersection between contagion theory and socio-ecological systems models. This is achieved using a population dynamics model between two groups characterised by a distinct food regime: omnivores and vegans. The greenhouse gas emissions of each food regime is used to estimate the city's changing carbon foodprint as the food regimes shift by social contagion. Social contagion is identified as a catalyst for social tipping points, and emission pathways are explored with a variety of different contagion variables to test sensitivity towards a tipping point. The main finding is that the urban carbon foodprint can be reduced significantly with widespread adoption of veganism, but that the foodprint reaches a minimum at 1.97 tonnes CO₂-equivalent per capita. This demonstrates the need to embed food demand in urban climate governance such as nudging towards plant-based food alternatives. Nudging is discussed as a lever of ecological importance to social contagion. Lastly, socio-ecological contagion is defined as the interactions between social contagion and damage done to ecological systems to measure peer-to-peer spread of environmental stewardship agendas, such as the journey to Veganville.     

Chimpanzees Show a Developmental Increase in Susceptibility to Contagious Yawning: A Test of the Effect of Ontogeny and Emotional Closeness on Yawn Contagion

Contagious yawning has been reported for humans, dogs and several non-human primate species, and associated with empathy in humans and other primates. Still, the function, development and underlying mechanisms of contagious yawning remain unclear. Humans and dogs show a developmental increase in susceptibility to yawn contagion, with children showing an increase around the age of four, when also empathy-related behaviours and accurate identification of others’ emotions begin to clearly evince. Explicit tests of yawn contagion in non-human apes have only involved adult individuals and examined the existence of conspecific yawn contagion. Here we report the first study of heterospecific contagious yawning in primates, and the ontogeny of susceptibility thereto in chimpanzees, Pan troglodytes verus. We examined whether emotional closeness, defined as attachment history with the yawning model, affected the strength of contagion, and compared the contagiousness of yawning to nose-wiping. Thirty-three orphaned chimpanzees observed an unfamiliar and familiar human (their surrogate human mother) yawn, gape and nose-wipe. Yawning, but not nose-wiping, was contagious for juvenile chimpanzees, while infants were immune to contagion. Like humans and dogs, chimpanzees are subject to a developmental trend in susceptibility to contagious yawning, and respond to heterospecific yawn stimuli. Emotional closeness with the model did not affect contagion. The familiarity-biased social modulatory effect on yawn contagion previously found among some adult primates, seem to only emerge later in development, or be limited to interactions with conspecifics. The influence of the ‘chameleon effect’, targeted vs. generalised empathy, perspective-taking and visual attention on contagious yawning is discussed.     

Yawn contagion and empathy in Homo sapiens

The ability to share others' emotions, or empathy, is crucial for complex social interactions. Clinical, psychological, and neurobiological clues suggest a link between yawn contagion and empathy in humans (Homo sapiens). However, no behavioral evidence has been provided so far. We tested the effect of different variables (e.g., country of origin, sex, yawn characteristics) on yawn contagion by running mixed models applied to observational data collected over 1 year on adult (>16 years old) human subjects. Only social bonding predicted the occurrence, frequency, and latency of yawn contagion. As with other measures of empathy, the rate of contagion was greatest in response to kin, then friends, then acquaintances, and lastly strangers. Related individuals (r≥0.25) showed the greatest contagion, in terms of both occurrence of yawning and frequency of yawns. Strangers and acquaintances showed a longer delay in the yawn response (latency) compared to friends and kin. This outcome suggests that the neuronal activation magnitude related to yawn contagion can differ as a function of subject familiarity. In conclusion, our results demonstrate that yawn contagion is primarily driven by the emotional closeness between individuals and not by other variables, such as gender and nationality.     

Landscape pattern and eco-hydrological charactedstics at the upstream of Minjiang River,China

Based on three scenes of Landsat 5 Thematic Mapper (TM) satellite images acquired on June 26,1994,12 land cover types were identified by the supervised classification techniques.The precipitation,runoff,and normalized difference vegetation index (NDVI) data of six catchments were accumulated from April to September in 1992,1993,and 1995.A new eco-hydrological index,expressed by the difference between precipitation and runoff divided by the product of precipitation and NDVI,was used in this study to represent the eco-hydrological functions of different catchments.The results were:(1) The selected six catchments at the upstream of Minjiang River,China were different in landscape patterns in terms of landscape type and cover.There were higher contagion,lower edge density and diversity index in the Shouxi catchments and lower contagion,higher edge density and diversity index in the Zagunao catchments.(2)Eco-hydrological indexes had remarkable differences among different catchments.The highest eco-hydrological index was found in the Shouxi catchments,which indicated higher precipitation holding capacity of vegetation therein.While the lower eco-hydrological index was found in the Zagunao catchments,which indicated its lower precipitation holding capacity of vegetation.(3) High correlation was detected between the landscape indexes and eco-hydrological indexes.Eco-hydrological index was positively correlated with landscape contagion in contrast with the negative correlation with landscape diversity and edge density.     

Spatial contagion drives colonization and recruitment of frogflies on clutches of red-eyed treefrogs

Spatial contagion occurs when the perceived suitability of neighbouring habitat patches is not independent. As a result, organisms may colonize less-preferred patches near preferred patches and avoid preferred patches near non-preferred patches. Spatial contagion may thus alter colonization dynamics as well as the type and frequency of post-colonization interactions. Studies have only recently documented the phenomenon of spatial contagion and begun to examine its consequences for local recruitment. Here, we test for spatial contagion in the colonization of arboreal egg clutches of red-eyed treefrogs by a frogfly and examine the consequences of contagion for fly recruitment. In laboratory choice experiments, flies oviposit almost exclusively on clutches containing dead frog eggs. In nature, however, flies often colonize intact clutches without dead eggs. Consistent with predictions of contagion-induced oviposition, we found that flies more frequently colonize intact clutches near damaged clutches and rarely colonize intact clutches near other intact clutches. Moreover, contagion appears to benefit flies. Flies survived equally well and suffered less parasitism on clutches lacking dead eggs. This study demonstrates how reward contagion can influence colonization dynamics and suggests that colonization patterns caused by contagion may have important population- and community-level consequences.     

Trajectories to extinction: spatial dynamics of the contraction of geographical ranges

Aim We examined the range contraction of 309 declining species of animals and plants to determine if the contraction dynamics better matched predictions based on the demographic characteristics of historical populations (demographic hypothesis) or based on the contagion‐like spread of extinction forces (contagion hypothesis). Location Species included in the analysis came from all biogeographic regions. Methods We obtained range maps for 309 species from literature or through personal correspondence with authorities. Hypotheses were contrasted by examining the sequence of changes in the proportion (C) of the remnant range that fell within the central region of the historical range. Monte Carlo simulations and polynomial regressions were employed to examine changes in C during the process of range contraction. Results The results of the Monte Carlo simulations indicated that more species had observed range contractions consistent with the contagion hypothesis than expected by chance (z‐score = 2.922, P = 0.002). The Monte Carlo analysis also indicated that the number of species whose observed range contractions were consistent with the demographic hypothesis was no greater than expected by chance (z‐score = 0.337, P = 0.367). The results of the polynomial regression analysis for the two most common taxonomic groups (mammals and birds) and for all geographical regions (Australia, Africa, Eurasia, and North America) we examined also supported the contagion hypothesis. Main conclusions Most of the examined range contractions are consistent with the contagion hypothesis and that the most likely contagion is human related disturbance. These results have important implications for the conservation of endangered species.     

Low relationship quality predicts scratch contagion during tense situations in orangutans (Pongo pygmaeus)

Primates show various forms of behavioral contagion that are stronger between kin and friends. As a result, behavioral contagion is thought to promote group coordination, social cohesion, and possibly state matching. Aside from contagious yawning, little is known about the contagious effect of other behaviors. Scratching is commonly observed during arousal and as such may play a role within group dynamics. While the Bornean orangutan (Pongo pygmaeus) is commonly considered the least social great ape, orangutans do engage in social interactions. Therefore, their social organization makes them a suitable case for studying the social function of behavioral contagion. Through behavioral observations of captive orangutans, we recorded all yawn and scratch events together with the corresponding behavior of all bystander group-members. As yawning was rarely observed, no conclusions could be drawn regarding this behavior. Scratching was contagious and occurred within 90 s after the triggering scratch. Specifically, orangutans showed increased scratch contagion when they had seen a weakly bonded individual scratch during tense contexts. When the orangutan had not seen the triggering scratch, the contagiousness of scratching was not affected by context or relationship quality. Our results indicate that behavioral contagion is not simply higher between individuals with stronger social relationships, but that the contagiousness of behaviors may vary based on the context and on social factors. We discuss these findings in light of an adaptive function that may reduce aggression.     

Distributional modelling and parsimony analysis of endemicity of Senecio in the Mediterranean-type climate area of Central Chile

Aim Floristic blocks and areas of endemism resulting from a parsimony analysis of endemicity (PAE) using raw floristic data versus data generated from distributional modelling for 130 species in the genus Senecio Tourn. ex L. distributed in the Mediterranean‐type climate area of Central Chile were compared, and the results were used to identify conservation priorities for the flora of the region. Location Central Chile, between 30° and 38° S. Methods Using herbarium records, a species × area matrix consisting of presence/absence data was constructed from a 0.5° × 0.5° grid. Distributional modelling techniques incorporating vegetation formations, elevation and the contagion index were used to interpolate floristic composition of poorly known areas. Parsimony analysis of endemicity was used to identify floristic blocks and areas of endemism. Results Using the number of most parsimonious trees as an index, distributional modelling greatly optimized the results of the PAE analysis. Three floristic blocks and four areas of endemism were suggested based on the PAE results using potential distribution data not incorporating the contagion index, while four blocks and two areas of endemism were suggested from the PAE results using potential distribution data incorporating the contagion index. Floristic blocks for the northern coast, southern Andes, and northern/central Andes were found, with some blocks showing divisions within them representing distinct geographic subunits. Major breaks between and within floristic blocks were identified at 32.5°–33° S and 34.5°–35° S. Main conclusions The floristic blocks identified with the distributional modelling and PAE correspond well to results from some previous studies and support hypothesized biogeographic divisions within Central Chile. The results were similar to those obtained from parallel analysis of the entire tree flora of Central Chile. The vegetative formation‐based distributional modelling produced robust and reproducible results when used along with PAE, especially when the contagion index was incorporated, and is a useful technique for area classification. The results demonstrate the utility of Senecio as an indicator genus for biogeography and conservation in southern South America.     

Both local presence and regional distribution of predator cues modulate prey colonisation in pond landscapes

Recent work on habitat selection has shown that the perceived quality of habitat patches may depend on the quality of adjacent patches. However, it is still unclear how local habitat selection cues can alter distribution patterns in metacommunities at a larger (regional) scale. We studied mosquito oviposition in pond landscapes that differed in the proportion of bad patches with fish predation risk. Our experiment provided conclusive evidence for two local and two regional types of habitat selection. Good patches near bad patches were avoided (local risk contagion) while more distant good patches experienced increased oviposition (regional compression). Oviposition in bad patches increased when located next to good patches (reward contagion) or when there were no good patches regionally present (regional compromise). This complex colonisation behaviour involving compromises at different spatial scales forces experimenters to reconsider the independence of spatial replicates and challenges available theories to predict species distribution patterns.     

Dispersion patterns of phytoplankton in lakes

The spatial distribution of phytoplankton is considered in relation to factors which may cause deviations from a random distribution. Such deviations may arise over a wide range of scales and attention is focused on small-scale contagion and its possible significance. Evidence is presented that contagion may occur at scales smaller than have previously been considered. Samples covering a range of volumes from 0.1 ml to 10 ml were taken from a small lake and total numbers of several phytoplankton species were counted in each sample to avoid problems arising from sub-sampling. The counts were used to calculate different indices of dispersion. All indices indicated contagion to occur at the scale being considered. Within the range examined the patch size appeared variable between species. The possible derivation and relevance of such micro-patchiness is discussed.     

Chimpanzees empathize with group mates and humans,but not with baboons or unfamiliar chimpanzees

Human empathy can extend to strangers and even other species, but it is unknown whether non-humans are similarly broad in their empathic responses. We explored the breadth and flexibility of empathy in chimpanzees, a close relative of humans. We used contagious yawning to measure involuntary empathy and showed chimpanzees videos of familiar humans, unfamiliar humans and gelada baboons (an unfamiliar species). We tested whether each class of stimuli elicited contagion by comparing the effect of yawn and control videos. After including previous data on the response to ingroup and outgroup chimpanzees, we found that familiar and unfamiliar humans elicited contagion equal to that of ingroup chimpanzees. Gelada baboons did not elicit contagion, and the response to them was equal to that of outgroup chimpanzees. However, the chimpanzees watched the outgroup chimpanzee videos more than any other. The combination of high interest and low contagion may stem from hostility towards unfamiliar chimpanzees, which may interfere with an empathic response. Overall, chimpanzees showed flexibility in that they formed an empathic connection with a different species, including unknown members of that species. These results imply that human empathic flexibility is shared with related species.     

Landscape pattern and eco-hydrological characteristics at the upstream of Minjiang River, China

Based on three scenes of Landsat 5 Thematic Mapper (TM) satellite images acquired on June 26, 1994, 12 land cover types were identified by the supervised classification techniques. The precipitation, runoff, and normalized difference vegetation index (NDVI) data of six catchments were accumulated from April to September in 1992, 1993, and 1995. A new eco-hydrological index, expressed by the difference between precipitation and runoff divided by the product of precipitation and NDVI, was used in this study to represent the eco-hydrological functions of different catchments. The results were: (1) The selected six catchments at the upstream of Minjiang River, China were different in landscape patterns in terms of landscape type and cover. There were higher contagion, lower edge density and diversity index in the Shouxi catchments and lower contagion, higher edge density and diversity index in the Zagunao catchments. (2) Eco-hydrological indexes had remarkable differences among different catchments. The highest eco-hydrological index was found in the Shouxi catchments, which indicated higher precipitation holding capacity of vegetation therein. While the lower eco-hydrological index was found in the Zagunao catchments, which indicated its lower precipitation holding capacity of vegetation. (3) High correlation was detected between the landscape indexes and eco-hydrological indexes. Eco-hydrological index was positively correlated with landscape contagion in contrast with the negative correlation with landscape diversity and edge density. __________ Translated from Acta Ecologica Sinica, 2005, 25(4): 691–698 [译自: 生态学报, 2005, 25(4): 691–698]     

不同尺度下城市景观综合指数的空间变异特征研究

在GIS与RS技术支持下,采用5 m分辨率的SPOT遥感图像数据,从城市土地利用角度,利用半变异函数对不同尺度的景观多样性、聚集度与分维数的空间变异进行了定量分析.结果表明,不同尺度下3种指数的空间变异具有相似特征,各个尺度上都具有空间依赖性,尺度越小,空间依赖性越大,空间变异的细节更显著,空间自相关性对总体变异的贡献逐渐增加,但尺度过小,有时会破坏景观内部结构.不同指数的半变异函数模型在相同尺度上差异显著,说明不同景观指数在不同尺度下的半变异函数模型不具可比性.就研究上海市内部土地利用结构而言,1 km的幅度是较合适的空间尺度.景观指数空间变异特征是尺度的函数,尺度对景观格局的影响不能忽视.景观综合指数对尺度响应的生态过程揭示了上海城市空间结构的规律性:在小尺度上的复杂无规律性,中尺度上的多中心性和大尺度上的圈层结构性,但各个尺度是相互依赖的,没有绝对界限.     

Modeling the adoption of innovations in the presence of geographic and media influences

While there is a large body of work examining the effects of social network structure on innovation adoption, models to date have lacked considerations of real geography or mass media. In this article, we show these features are crucial to making more accurate predictions of a social contagion and technology adoption at a city-to-city scale. Using data from the adoption of the popular micro-blogging platform, Twitter, we present a model of adoption on a network that places friendships in real geographic space and exposes individuals to mass media influence. We show that homophily both among individuals with similar propensities to adopt a technology and geographic location is critical to reproducing features of real spatiotemporal adoption. Furthermore, we estimate that mass media was responsible for increasing Twitter's user base two to four fold. To reflect this strength, we extend traditional contagion models to include an endogenous mass media agent that responds to those adopting an innovation as well as influencing agents to adopt themselves.     

Spatial organization in sympatric populations of Apodemus sylvaticus and A. flavicollis (Rodentia: Muridae)

The spatial organization and relationships of Apodemus sylvaticus and A. flavicollis in mixed deciduous woodland were examined using live-trapping techniques. Each population was aggregated and contagion was greatest during early summer. Aggregation in A sylvaticus varied inversely with density so that at high densities this species was randomly dispersed. In A. flavicollis aggregation increased with increasing density. This interspecific difference may result from differing annual population cycles. Adult males, adult females and juveniles had different patterns of dispersion and association in A. sylvaticus and A. flavicollis suggesting differences in their social behaviour. Intraspecific associations, particularly among males and between males and females, made a major contribution to overall contagion in the populations. A. sylvaticus and A. flavicollis were segregated throughout the year except for late summer and they were also prevalent in different cover types. The behaviour which determined the spatial segregation of the species may be acquired since juvenile A. sylvaticus were associated more frequently with A. flavicollis and juvenile A. flavicollis were associated less frequently with A. sylvaticus than their respective adult conspecifics. Comparing sympatric with allopatric populations of A. sylvaticus , and observing inter-specific behaviour, suggest that the spatial segregation in sympatry results from A. sylvaticus avoiding the competitively superior A. flavicollis .