Testate amoebae as proxy for water level changes in a brackish tidal marsh

Few studies have examined testate amoebae assemblages of estuarine tidal marshes. This study investigates the possibility of using soil testate amoebae assemblages of a brackish tidal marsh (Scheldt estuary, Belgium) as a proxy for water level changes. On the marsh surface an elevation gradient is sampled to be analyzed for testate amoebae assemblages and sediment characteristics. Further, vegetation, flooding frequency and soil conductivity have been taken into account to explain the testate amoebae species variation. The data reveal that testate amoebae are not able to establish assemblages at the brackish tidal marsh part with flooding frequencies equal to or higher than 36.5%. Further, two separate testate amoebae zones are distinguished based on cluster analysis. The lower zone’s testate amoebae species composition is influenced by the flooding frequency (~ elevation) and particle size, while the species variability in the higher zone is related to the organic content of the soil and particle size. These observations suggest that the ecological meaning of elevation shifts over its range on the brackish tidal marsh. Testate amoeba assemblages in such a brackish habitat show thus a vertical zonation (RMSEP: 0.19 m) that is comparable to the vertical zonation of testate amoebae and other protists on freshwater tidal marshes and salt marshes

The dual role of media internalization in adolescent sexual behavior

Sexualizing media content is prevalent in various media types. Sexualizing media messages and portrayals emphasize unattainable body and appearance ideals as the primary components of sexual desirability. The internalization of these ideals is positively related to self-objectification and sexual body consciousness. In turn, self-objectification and sexual body consciousness affect adolescents’ sexual behavior, albeit in opposing directions. While objectifying self-perceptions are linked to higher levels of sexual behavior, body consciousness during physical intimacy is linked to lower levels of sexual behavior. Based on this knowledge, the present three-wave panel study of 824 Belgian, predominant heterosexual adolescents (Mage = 15.33; SD = 1.45) proposes a dual-pathway model that investigates two different pathways through which the internalization of media ideals may impact adolescents’ sexual behavior. An inhibitory pathway links media internalization to lower levels of sexual behavior through sexual body consciousness, and a supportive pathway links media internalization to higher levels of sexual behavior through self-objectification. Structural equation analyses supported the proposed dual-pathway, showing that the impact of media internalization on adolescents’ sexual behavior proceeds through an inhibitory pathway and a supportive pathway. Regarding the supportive pathway, media internalization (W1) positively predicted sexual behavior (W3), through valuing appearance over competence (W2). Regarding the inhibitory pathway, media internalization (W1) positively predicted body surveillance, which, in turn, positively predicted sexual body consciousness (all W2). Sexual body consciousness (W2) is negatively related to sexual behavior (W3). From a sexual developmental perspective, these findings emphasize the importance of guiding adolescents in interpreting and processing sexualizing media messages

Social Media Browsing and Adolescent Well-Being: Challenging the “Passive Social Media Use Hypothesis”

A recurring hypothesis in the literature is that "passive" social media use (browsing) leads to negative effects on well-being. This preregistered study investigated a rival hypothesis, which states that the effects of browsing on well-being depend on person-specific susceptibilities to envy, inspiration, and enjoyment. We conducted a three-week experience sampling study among 353 adolescents (13-15 years, 126 assessments per adolescent). Using an advanced N = 1 method of analysis, we found sizeable heterogeneity in the associations of browsing with envy, inspiration, and enjoyment (e.g., for envy ranging from β = -.44 to ß = +.71). The Passive Social Media Use Hypothesis was confirmed for 20% of adolescents and rejected for 80%. More adolescents with browsing-induced envy experienced negative effects on affective well-being (25%) than adolescents with no browsing-induced envy (13%). Conversely, more adolescents with browsing-induced enjoyment experienced positive effects on affective well-being (47%) than adolescents with no browsing-induced enjoyment (9%). Lay summary: 'A recurrent question among academics is whether social media browsing negatively affects teens' well-being. Some scholars believe that this browsing can lead to envy and declines in well-being. Others think that it can also lead to inspiration and enjoyment, and to increases in well-being. To investigate which scholars are right, we asked 353 teens to report six times a day for a period of three weeks how often they had browsed Instagram and Snapchat in the past hour. Furthermore, we asked them how much envy, inspiration, and enjoyment they had experienced in that hour, and how well they felt at that moment. We found sizeable differences among teens in the effects of browsing on well-being at that moment. While one group of teens (20%) felt worse after browsing, another group (17%) felt better. More teens who had felt envy while browsing, experienced negative effects on well-being than teens who did not feel such envy while browsing. Conversely, more teens who had felt enjoyment while browsing, experienced positive effects on well-being than teens who had not felt such enjoyment

Social Media Use and Friendship Closeness in Adolescents’ Daily Lives: An Experience Sampling Study

The formation and maintenance of friendship closeness is an important developmental task in adolescence. To obtain insight in real-time processes that may underly the development of friendship closeness in middle adolescence, this preregistered experience sampling study [ESM] investigated the effects of social media use on friendship closeness. The study was conducted among 387 adolescents (54% girls; Mage = 14.11 years; 96% Dutch) from different educational tracks (44% lower prevocational secondary education, 31% intermediate general secondary education, 26% academic preparatory education). Adolescents reported six times per day for 3 weeks on their Instagram, WhatsApp, and Snapchat use in the previous hour and their momentary experiences of friendship closeness (126 assessments; 34,930 observations). Multilevel analyses revealed positive between-person associations of friendship closeness with general WhatsApp use and Instagram use with close friends. In contrast, at the within-person level, we found small negative overall associations of general WhatsApp use and Instagram use (with and without close friends) with friendship closeness. However, there was large heterogeneity in the person-specific effect sizes of the within-person associations of social media use with friendship closeness. For example, person-specific effect sizes of the association of Instagram use with close friends with friendship closeness ranged from β = −.745 to β =.697. These results underline the importance of acknowledging person-specific effects in developmental and media effect theories. (PsycInfo Database Record (c) 2021 APA, all rights reserved

Some socially poor but also some socially rich adolescents feel closer to their friends after using social media

Who benefits most from using social media is an important societal question that is centered around two opposing hypotheses: the rich-get-richer versus the poor-get-richer hypothesis. This study investigated the assumption that both hypotheses may be true, but only for some socially rich and some socially poor adolescents and across different time intervals. We employed a state-of-the-art measurement burst design, consisting of a three-week experience sampling study and seven biweekly follow-up surveys. Person-specific analyses of more than 70,000 observations from 383 adolescents revealed that 12% of the socially rich adolescents (high in friendship support or low in loneliness) felt closer to their friends after using social media, as opposed to about 25% of the socially poor adolescents (low in friendship support or high in loneliness). However, only 1 to 6% of all adolescents (socially rich and poor) felt closer both in the short- and longer-term. These results indicate that the rich-get-richer and the poor-get-richer hypotheses can hold both, but for different adolescents