Displacement Hypothesis Research Articles

THE PARADOX OF DIGITAL CONNECTIVITY: COMPARING THEORIES ON LONELINESS AND MOBILE PHONE DEPENDENCE

Abstract In the Digital Age, smartphones and tablets are widespread, but their impact on well-being, particularly the relationship between loneliness and mobile phone dependence (nomophobia), remains debated. The direction of this relationship is unclear, with limited research across the lifespan. This study examines two theories: the Displacement Hypothesis, which suggests that nomophobia leads to loneliness, and the Theory of Compensatory Internet Use (CIUT), which proposes that loneliness drives nomophobia. Data were collected from 550 adults (Mage = 40.15, SD = 12.23, 54% female; 59% non-Hispanic White) via an online survey, delivered on Prolific. Linear regression models, adjusting for sociodemographics (age, gender), evaluated the relationship between measures of mobile phone dependence (Nomophobia Questionnaire) and loneliness (UCLA Loneliness Scale). For the model with loneliness as an outcome, (N = 550), age (β = -0.10, p =.028) and nomophobia (β = 0.06, p =.003) were significant predictors. For the model with nomophobia as an outcome, (N = 550), age (β = -0.35, p <.001), gender (β = -6.40, p =.009), and loneliness (β = 0.28, p =.003) were significant predictors. Both directions showed a significant relationship, however, the model with loneliness as a predictor of nomophobia explained slightly more variance (4.6%) in the outcome (vs 2.5% for nomophobia predicting loneliness). Results suggest that reducing loneliness could help mitigate mobile phone dependence. Future longitudinal research could further clarify the relationship between loneliness and nomophobia, providing more evidence for either the CIUT or the Displacement Hypothesis.

Smaller islands, bigger appetites: evolutionary strategies of insular endemic skinks.

Competitive dietary and morphological divergence among co-occurring species are fundamental aspects of ecological communities, particularly on islands. Cabo Verde (~570 km west of continental Africa) hosts several endemic reptiles descended from common ancestors, with sympatric species exhibiting wide morphological variation and competing for limited resources. To explore the mechanisms of resource partitioning between coexisting species, DNA metabarcoding was used to compare the diets of large and small skinks, Chioninia vaillantii and Chioninia delalandii, in sympatric and allopatric contexts on Fogo Island and in a more competitive context on the small and resource-poor Cima Islet. The morphological variation of all populations was also examined to test the character displacement hypothesis and to compare the effect of different competitive scenarios. Results showed significant differences in diet and linear measurements between species and populations. The two sympatric populations of C. delalandii on Fogo and Cima showed similar changes in head morphology compared to the allopatric population, supporting character displacement. The effect of higher competitive pressure on Cima was evidenced by the increased morphological and dietary variation observed. This study demonstrates how sister species develop dietary adaptations/morphologies to maintain stable coexistence, especially in highly competitive scenarios, providing useful insights for effective conservation strategies.

A Psychophysiological Investigation of Mechanisms Underlying "Feeling Fat" in Women With and WithoutBinge Eating.

"Feeling fat", the somatic experience of being overweight not fully explained by objective body weight, is considered to be an eating pathology maintenance factor. The traditional clinical understanding of "feeling fat" is based on the body displacement hypothesis, which suggests that negative emotions are projected onto the body and experienced as "feeling fat" in lieu of adaptive emotion regulation. A more recent theory suggests that "feeling fat" occurs in response to thought-shape fusion (TSF), a cognitive distortion in response to the imagined consumption of perceived fattening food. The present experimental study compared the roles of these two proposed mechanisms of "feeling fat" using self-report and psychophysiological measures. Eighty-two women (41 with binge eating, 41 control participants) self-reported "feeling fat" and had their heart rate variability (HRV), a physiological index of emotion regulation, measured before and after imagined inductions. Participants imagined either a personalized negative affective experience or consuming a preferred, so-called 'fattening' food. The TSF induction increased self-reports of "feeling fat" among participants with binge eating but not among control women. The negative affect induction did not increase self-reported "feeling fat" in either group. HRV did not significantly change in response to either induction for either group. TSF may be a more potent precursor to "feeling fat" than negative affect for individuals with binge eating. This may suggest new treatment directions, such as cognitive defusion from TSF when patients experience "feeling fat." The utility of HRV in monitoring "feeling fat" is questionable.

A test of the mechanistic process behind the convergent agonistic character displacement hypothesis.

In this era of rapid global change, understanding the mechanisms that enable or prevent species from co-occurring has assumed new urgency. The convergent agonistic character displacement (CACD) hypothesis posits that signal similarity enables the co-occurrence of ecological competitors by promoting aggressive interactions that reduce interspecific territory overlap and hence, exploitative competition. In northwestern Switzerland, ca. 10% of Phylloscopus sibilatrix produce songs containing syllables that are typical of their co-occurring sister species, Phylloscopus bonelli ("mixed singers"). To examine whether the consequences of P. sibilatrix mixed singing are consistent with CACD, we combined a playback experiment and an analysis of interspecific territory overlap. Although P. bonelli reacted more aggressively to playback of mixed P. sibilatrix song than to playback of typical P. sibilatrix song, interspecific territory overlap was not reduced for mixed singers. Thus, the CACD hypothesis was not supported, which stresses the importance of distinguishing between interspecific aggressive interactions and their presumed spatial consequences.

Is Bedtime Media Use Good or Bad? A Competitive Analysis Between the Sleep Displacement Hypothesis and the Media Recovery Hypothesis

ABSTRACT Bedtime media use is often maligned in research and pop culture. However, the evidence for the relationship between bedtime media use and sleep for adults has been mixed – sometimes sleep quality is negatively affected by media use, sometimes it is positively affected. Competing explanations include the sleep displacement hypothesis (i.e. media use leads to later sleep onset, less total sleep, and lower sleep quality) and the media recovery hypothesis (i.e. media use helps reduce stress, and this relaxation helps people fall and stay asleep). Two retrospective diary studies test these competing hypotheses in an undergraduate sample (n = 200) and a general population U.S. adult sample (n = 202). Overall, results provide more support for the sleep displacement hypothesis than for the media recovery hypothesis. However, some evidence suggests potential for positive relationships between media use and sleep. More work is needed to explicate the complicated relationship between bedtime media use and sleep.

Retinal displacement after surgery for idiopathic macular hole.

To review and summarize the mechanism hypothesis, influencing factors and possible consequences of macular retinal displacement after idiopathic macular hole (IMH) surgery. PubMed and Web of Science database was searched for studies published before April 2023 on "Retinal displacement", "Idiopathic macular holes", and "Macular displacement". Recently, more academics have begun to focus on retinal displacement following idiopathic macular holes. They found that internal limiting membrane (ILM) peeling was the main cause of inducing postoperative position shift in the macular region. Moreover, several studies have revealed that the macular hole itself, as well as ILM peeling method, will have an impact on the result. In addition, this phenomenon is related to postoperative changes in macular retinal thickness, cone outer segment tips line recovery, the occurrence of dissociated optic nerve fiber layer (DONFL) and the degree of metamorphopsia. As a subclinical phenomenon, the clinical significance of postoperative macular displacement cannot be underestimated as it may affect the recovery of anatomy and function.

Self-disgust mediates the effect of problematic mobile social media use on non-suicidal self-injury in adolescents: A latent growth curve analysis.

Previous research linked problematic mobile social media use to non-suicidal self-injury (NSSI). However, little research explored the underlying mechanism. Drawing on the social displacement hypothesis, which suggests that excessive social media use may disrupt offline social interactions, leading to negative emotional experiences, the study employs a longitudinal design to explore the relationship between problematic mobile social media use and NSSI, with a specific emphasis on the mediating role of self-disgust. A total of 1,684 Chinese adolescents (52.3% females; Mage = 14.59 years, SDage = 1.27) completed self-report questionnaires regarding problematic mobile social media use, self-disgust, and NSSI. The assessment was conducted in three waves, 6 months apart. Using latent growth curve and structural equation modeling, our study observed a consistent linear decline in NSSI levels over time. Higher initial NSSI levels correlated with a slower reduction. Problematic mobile social media use positively influenced the initial level of NSSI. Additionally, self-disgust played a mediating role in the relationship between problematic mobile social media use and NSSI. The study underscores the importance of understanding the emotional experiences behind social media use, beyond mere usage duration. By revealing the mediating role of self-disgust, it provides new insights into the complex interplay between problematic mobile social media use and adolescent NSSI.

A simple structure with two different linear regimes

We perform an asymptotic static analysis on a simple two degrees of freedom structure, made up of a highly stiff bar and two springs, which shows two different linear behaviours and different finite stiffness depending on the magnitude of an applied static force. Both regimes as well as the non-linear transition between them occur in the framework of small forces and displacements. The problem gives physical insight to the relations between linearity and small displacement hypothesis and it is suitable for a first course in asymptotic analysis to students with basic skills in structural or rational mechanics.

Time Spent Using Digital Technology, Loneliness and Well-Being Among Three Cohorts of Adolescent Girls and Boys – A Moderated Mediation Analysis

Significant changes to daily life and educational routines due to the COVID-19 pandemic resulted in changes in social interactions and might have contributed to an increase in screen-based activities, loneliness, and mental health issues among adolescents. Two years after the pandemic outbreak, the present study examined the relationships between time spent using digital technology (DT), loneliness and well-being among three cohorts of adolescents in Croatia. A moderated mediation model of relationship between time spent using DT and well-being was tested, with loneliness as a potential mediator and gender as a moderator. A nationally representative sample included 3706 11-year-olds, 3866 13-year-olds and 8815 17-year-olds. The study was conducted in lower and upper secondary schools in the spring of 2022. The questionnaire contained a single item self-report measure of time spent using DT and loneliness, while the adapted WHO-5 was used for measuring adolescents’ well-being. Results indicated that time spent using DT was positively associated with loneliness and negatively associated with well-being. Loneliness mediated the relationship between time spent using DT and well-being in all cohorts. This mediation was moderated by gender in the group of 11-year-olds only. Gender moderated the direct effect on well-being among 11- and 13-year-olds. Effects were stronger among girls and younger participants. The results are discussed in light of the displacement hypothesis, which posits that negative effects on well-being are a consequence of the replacement of in-person activities with screen-based activities.

SHAPE OF CENTRAL BANK MONEY AIMS FOR DIGITAL PROGRAMMABLE COINS: FROM METAL AND PAPER TO A FULLY CONTROLLED DIGIT (DISPLACEMENT HYPOTHESIS)

SHAPE OF CENTRAL BANK MONEY AIMS FOR DIGITAL PROGRAMMABLE COINS: FROM METAL AND PAPER TO A FULLY CONTROLLED DIGIT (DISPLACEMENT HYPOTHESIS)

Caught in the web: a meta-analysis of Internet addiction, excessive daytime sleepiness and depressive symptoms in adolescents

PurposeIn response to growing concerns over the negative consequences of Internet addiction on adolescents’ mental health, coupled with conflicting results in this literature stream, this meta-analysis sought to (1) examine the association between Internet addiction and depressive symptoms in adolescents, (2) examine the moderating role of Internet freedom across countries, and (3) examine the mediating role of excessive daytime sleepiness.Design/methodology/approachIn total, 52 studies were analyzed using robust variance estimation and meta-analytic structural equation modeling.FindingsThere was a significant and moderate association between Internet addiction and depressive symptoms. Furthermore, Internet freedom did not explain heterogeneity in this literature stream before and after controlling for study quality and the percentage of female participants. In support of the displacement hypothesis, this study found that Internet addiction contributes to depressive symptoms through excessive daytime sleepiness (proportion mediated = 17.48%). As the evidence suggests, excessive daytime sleepiness displaces a host of activities beneficial for maintaining mental health. The results were subjected to a battery of robustness checks and the conclusions remain unchanged.Practical implicationsThe results underscore the negative consequences of Internet addiction in adolescents. Addressing this issue would involve interventions that promote sleep hygiene and greater offline engagement with peers to alleviate depressive symptoms.Originality/valueThis study utilizes robust meta-analytic techniques to provide the most comprehensive examination of the association between Internet addiction and depressive symptoms in adolescents. The implications intersect with the shared interests of social scientists, health practitioners, and policy makers.

Taphonomy of the fauna and chert assemblages from the Middle Palaeolithic site of Vajo Salsone, Eastern Italian Alps

The Vajo Salsone site is located at an altitude of 376m a.s.l. on the right slope of the Valpantena valley, in the Veneto Pre-Alps, north of the town of Verona. The site was discovered in 2017 during the construction of a truckable road. It is a small and narrow karst cavity filled with Pleistocene sediments that yield abundant Middle Palaeolithic artefacts and faunal remains, often coated by carbonate encrustations. The lithic assemblage shows the predominance of the Levallois method and is characterised by a large number of retouched elements, including foliated points. These artefacts, typical of the Late Middle Palaeolithic period in central and south-eastern Europe, make Vajo Salsone an exceptional case, as their recovery is rather sporadic west of the Balkan Peninsula and south of the Alps. The fauna is dominated by ungulates, the most abundant being the red deer followed by roe deer, chamois and elk. Among the carnivores, wolf is common, while fox and bear are rare. This fauna suggests an environment characterised by open glades and closed forests, with a discontinuous presence of alpine grasslands and wetlands. Taphonomic analysis of the bone surfaces is complicated by the presence of concretions on most of the remains, which also show a high degree of fragmentation. Post-depositional fractures are common, and weathering is light. Only cervid bones show anthropogenic modifications related to hunting and hominin exploitation such as cut marks, scraping, impacts and burnt modifications. Some long bone diaphysis bear marks testifying to the use of these fragments as retouchers for flint artefacts. Such use has been evidenced at other Middle Palaeolithic sites in the area. Furthermore, the good state of preservation of the occlusal surface enamel of the cervid teeth allowed us to carry out meso and microwear analyses which provided data on seasonality and site occupation. With regard to dental wear analysis, the red deer from Vajo Salsone had mesowear suggesting a mixed feeding and grazing diets, whereas microwear analysis showed that the individuals had a diet between mixed feeding and browsing. The taphonomic study of the site has been integrated by X–RFS analysis of the alterations occurred to the lithic artefacts, which include deep patination and the formation of calcareous crusts. All the data presented here are consistent with the hypothesis of a short-distance displacement of the material from a single archaeological deposit possibly related to human occupation during the warm season.

Influence of generalist stingless bees on the structure of mutualistic flower–pollinator networks in the tropics: Temporal variation

Abstract Stingless bees (Meliponini) are expected to play a central role in structuring mutualistic networks in the Neotropics, as they are generalist and often abundant pollinators. Living in populous social colonies with a perennial life cycle, they require continuous large amounts of resources and often forage on abundant flowerings such as mass‐flowering throughout the year. In this field research, we seek to understand how temporal variations on foraging activity of stingless bees and abundance of mass‐flowering partner plants affect the topology of the plant–pollinator mutualistic networks. The networks were compared between spring and summer, periods of high and low abundances of flowerings and mass‐flowering, respectively. Bees were sampled on flowers, in replicates of floodplain fields in Atlantic Forest of southern Brazil. Interactions with partner plants were considered effective only when bees had pollen on their bodies (potential pollinators). Through analysis of pollen grains attached to their bodies, several topological metrics of networks and functional categories were obtained. The robustness or networks resistance to secondary species loss due to simulated focal species extinction was also measured. The networks maintained similar general structure throughout the year (high nestedness, moderate modularity and connectance, low community‐level specialisation and negative dependency asymmetry). Particularly, nestedness and dependency asymmetry did not change between the two seasons. Community‐level specialisation was higher in summer, contrary to expectations, when there was a collapse in the supply of floral resources and also a reduction in the abundance and foraging pressure of stingless bees. As there was also a greater number of specialist pollinators in summer, the hypothesis of temporal displacement due to foraging pressure from generalists was proposed. At the same time, stingless bees oscillated between network hubs in spring and connectors in summer, reflecting the variation in their abundance between these two seasons. In spring, the greater concentration of foraging by these generalists in the abundant mass‐flowering probably attenuated their diffuse competitive pressure on all other pollinators, even though the foraging overlap was higher in this period. In this period of high abundance of floral resources, specialist pollinators capable of expanding the realised niche are active. Based on recent theoretical conclusions of dynamic model of mutualistic networks structure that incorporated effects of inter‐specific competition and adaptive foraging, we argue that the adaptive foraging of generalist and abundant stingless bees contributes in an important way to the high nestedness and robustness of networks, which ultimately favour the coexistence of species in the long term. Particularly, taking the high intra‐annual turnover of bee and plant species between the two seasons, and the similar floral constancy of both generalist stingless bees and specialist pollinators, we also infer that stingless bees act as generalised pollinators in the networks rewiring throughout the year.

Associations between physical activity and digital gaming activity among Finnish adolescents

Abstract Background Physical activity (PA) for adolescents is an important health promotion habit to develop, yet other activities may be more appealing during this stage in life. According to the displacement hypothesis, time on digital games takes away the opportunity to be physically active. As there is a notable decline in PA levels between the ages of 11y- 15y in Finland, there is an urgent need to investigate potential areas that contribute to the decline. According to the 2021 Finnish Player Barometer, 65% of Finns play digital games regularly. The aims of this study were to investigate the associations between PA and digital gaming, and to examine how these associations may change by gaming genres. Methods A Finnish national representative sample (n = 1979) of 11y-15y olds, completed a self-report survey in spring 2022. Variables included PA behaviour, the frequency of digital gameplay, by sport simulation and Esports genres, and various confounders (gender, age, disability, economic status). Analyses were carried out by chi-square tests and multi-logistic regression analyses (no/low activity as reference categories). Results A third (32%) reported daily PA. Daily digital gameplay was more common among males (74%) than females (26%) and decreased from 11y (53%), 13y (30%) to 15y (17%) olds. After controlling for confounders, playing ball sport simulations (e.g. FIFA) was associated with taking part in 5 or more days/week of PA, or sport club participation (OR = 2.8, CI = 1.7-4.4), whereas playing a lot of first-person shooter games, as an Esport, was negatively associated with sport club participation (OR = 0.6, CI = 0.4-0.9) when compared to the reference categories. Conclusions The displacement hypothesis was supported partly among Esport players, but not by simulated sport gamers. Targeted interventions to promote physical activity with digital gaming, require a genre-specific approach. Key messages • Associations between physical activity and digital gaming activity among young adolescents is genre specific. • Frequent playing of digital games were more common among male 11-15y olds than females.

Changes in adolescent physical activity levels pre and post COVID-19 in Ireland

Abstract Background The World Health Organisation (WHO) recommends moderate to vigorous physical activity (MVPA) for at least, on average, 60 minutes per day, and muscle strengthening exercises at least three times a week for adolescent health. Lockdowns, sports club and school closures during COVID-19 limited children's PA opportunities. The aim of this study was to examine changes in PA behaviour among students in schools undertaking a PA intervention (the Active School Flag: ASF) over three consecutive years. Methods ASF is a whole school intervention. Its aim is to increase student PA opportunities and thus, PA levels. ASF implementation team includes students, teachers and school management. Using a repeated cross-sectional panel study design, all students in five pilot ASF schools were invited to complete the ASF whole-school survey in September 2019, 2020 and 2021. Descriptive statistics, contingency tables and multi-logistic regression analyses evaluated changes in PA behaviour over time. Results Students in five schools (N = 7530, 33% male; 65% female, 2% other) took part. Physical inactivity (WHO guidelines for only 0-2days) dropped from 25% in 2019 to 22% in 2020 and 23% in 2021. Analysis by gender showed females to be most active in 2020 (p = .004). No significant changes, over time, were found for muscle-strengthening exercises. Four out of the five schools reported a significant increase in active travel and a decrease in car transport behaviour from 2019-2021, no gender differences were found. Conclusions COVID-19 public health restrictions varied over the duration of this study (higher in 2020 than at other time points). Little or no change in overall PA or muscle-strengthening exercises was established, yet significant increases in active transport to and from school were reported. Further research should explore mechanisms and the potential of a displacement hypothesis for types of PA change during this time. Key messages • COVID-19 movement restrictions, such as lockdowns, school and sports club closures contributed to increases in active transport to and from school, while other forms of PA remained largely unchanged. • The Active School Flag may be an effective programme to reduce the amount of students who are physically inactive.

Damping characteristics and sound transmission loss of finite composite plates with frequency dependent constrained viscoelastic interlayer

This paper proposes a sublaminate layer-wise finite element modeling method to accurately evaluate the damping and sound insulation characteristics of composite constrained layer damping plates. It incorporates the frequency-dependent property of viscoelastic interlayer into fully coupled structure-acoustic interaction equations, and employs the generalized high-order displacement hypothesis with tailored polynomial series expansion. The method is applicable to various boundary conditions and material layer combinations. Validation is conducted using numerical and experimental data. Parametric study identifies optimal thickness and stiffness for maximizing modal loss factor. Additionally, sound insulation performance is examined in narrow frequency bands, highlighting the damping enhancement of viscoelastic interlayer.

Online News Displaces Print Newspaper: Media Students' Preferences and Perceptions

This study extends the uses and gratifications theory to explore the uses of general, time, daily, and weekly news. It also applies the theory of media displacement to investigate the ease, preference, emergency use, credibility perception, and confidence in forming opinions for news from print newspapers and online sources. A survey with 244 students from communication and media disciplines in Lahore's universities revealed that 68% of media students read news for only 30 minutes daily. 65% preferred daily updates and found it easier to access news online (62%). During emergencies, 79% relied on online news, but only 52% considered it authentic. Despite concerns about tree wastage, 67% favoured free access to online news, with only 33% willing to purchase print newspapers. This study supports the media displacement hypothesis, suggesting that online news is displacing print newspapers due to affordability, posing significant implications for newspaper management.

Application of the Displacement Hypothesis to Find the Resistance to a Viscous Fluid Flow Around Bodies

Application of the Displacement Hypothesis to Find the Resistance to a Viscous Fluid Flow Around Bodies

Character displacement of egg colors during tinamou speciation.

The divergence of reproductive traits frequently underpins the evolution of reproductive isolation. Here we investigated whether tinamou (Tinamidae) egg colorations function as mating signals that diverged as character displacement (mating signal character displacement hypothesis). We tested three evolutionary predictions behind the hypothesis: (a) egg colors coevolve with known mating signals; (b) signal divergence is associated with divergent habitat adaptation; and (c) sympatric tinamou species with similar songs have different egg colors as character displacement during speciation. We found support for all three predictions. In particular, egg colors coevolved with songs; songs and egg colors coevolved with habitat partitioning; and tinamou species that were likely sympatric with similar songs tended to have different egg colors. In conclusion, the mating signal character displacement hypothesis is well supported in which egg colors serve as mating signals that undergo character displacement during tinamou speciation.

Internet use and Chinese migrant older adults' life satisfaction: A panel data study

AbstractThis article explores the association between internet use and Chinese migrant older adults' life satisfaction based on the displacement hypothesis. Using 2016 and 2018 China Family Panel Studies (CFPS) data, we find that internet use is significantly associated with lower life satisfaction. The association is stronger in the female, age 71 and above and low‐income groups. Mediation analysis suggests that social capital has a significant mediating effect in linking internet use and life satisfaction, accounting for about 25% of the total effect of internet use. Based on the findings, we recommend appropriate interventions for internet use and promote social inclusion of migrant older adults, so as to further improve their quality of life.