The study, conducted by Bomi Jin and Lonn Lanza-Kaduce of the Department of Sociology and Criminology & Law at the University of Florida, is published in the American Journal of Criminal Justice. Rather than treating schools simply as protective institutions that supervise young people, the authors reframe them as structured social environments that organize adolescents’ face-to-face interactions — including interactions with marijuana-using peers. When schools closed, that organizing structure dissolved; when they reopened, it snapped back, with measurable consequences for the transmission of substance use behavior through peer networks.

The theoretical foundation draws on Akers’ social structure and social learning framework, an extension of Edwin Sutherland’s classic differential association theory. In its simplest form, differential association holds that criminal and deviant behavior is learned through interaction with intimate personal groups, where individuals acquire not only the techniques of deviance but also the attitudes, definitions, and reinforcement patterns that sustain it. Social learning theory, developed by Ronald Akers and colleagues, added mechanisms of differential reinforcement, imitation, and definitions favorable or unfavorable to law-violating behavior. Meta-analytic reviews have consistently ranked peer associations among the strongest predictors of adolescent delinquency and substance use. What the structural branch of the theory adds is the insight that macro-level and organizational contexts — neighborhoods, communities, and schools — pattern the frequency, duration, priority, and intensity of those associations.

Jin and Lanza-Kaduce seized on a rare analytical opportunity embedded in the pandemic. Because Florida school districts resumed in-person instruction at different points during the 2020–2021 academic year, students across the state faced sharply different levels of in-person peer contact at the same moment in time. The researchers used this variation in school return timing as a proxy for the degree of face-to-face interaction adolescents had with their peers. Students in early-returning districts were reimmersed in hallways, classrooms, lunchrooms, and after-school spaces where friendships are enacted bodily — through conversation, shared routines, and what interactionist scholars call interaction rituals — while late returnees remained more dependent on digital communication, which prior research suggests carries weaker or at least different socialization signals than physical co-presence.

The empirical analysis drew on statewide survey data from Florida middle and high school students in grades 6 through 12, with an analytical sample of 7,656 adolescents. The data came from the Florida Youth Substance Abuse Survey, an instrument designed to measure risk and protective factors for adolescent substance use and problem behaviors. The outcome of interest was adolescents’ own marijuana use, and the central explanatory variable was friends’ marijuana use, alongside the school return timing that distinguished early returnees from later ones. The models also controlled for established individual and family-level predictors, including low self-control, measured through items adapted from Grasmick and colleagues’ widely used scale, and parental monitoring, with full item wording provided in the study’s online supplement.

Methodologically, the study confronted several challenges familiar to survey researchers. Missing data were substantial and, importantly, not missing completely at random: additional analyses following the approach of Meldrum and colleagues revealed significant mean differences on study variables between cases with and without missing responses, undermining the assumption of randomness. The authors therefore employed multiple imputation using chained equations, a modern technique that preserves uncertainty while filling in missing values based on observed relationships. Because marijuana use in the sample was a relatively low-prevalence behavior, which can bias maximum-likelihood estimates in logistic regression, the researchers also ran penalized Firth logistic regressions, a technique designed to stabilize estimates for rare events; the substantive conclusions were unchanged. To interpret the interaction between school return timing and friends’ use in a nonlinear probability model, the study drew on contemporary best practices for presenting and testing interaction effects in generalized linear models.

The results split cleanly into two parts. Evidence for mediation — the idea that returning to school earlier indirectly increases marijuana use by increasing friends’ marijuana use — was, in the authors’ words, limited. The structural timing of school reopening did not simply manufacture new marijuana-using friendships that then produced use. Instead, the striking finding was moderation: the association between friends’ marijuana use and adolescents’ own use was substantially stronger among early returnees than among later returnees. In other words, having marijuana-using friends predicted a student’s own marijuana use much more powerfully when those friendships were being enacted in person at school. The effect was particularly pronounced among adolescents with multiple marijuana-using friends, suggesting a dose-response pattern in which exposure to several using peers, combined with daily physical co-presence, created the strongest gravitational pull toward use.

These findings carry weight for how scientists understand the mechanics of peer influence. Social learning researchers have long distinguished between what peers think and what peers do, and laboratory and field work on ‘deviancy training’ has shown that adolescent friendships can become engines of reinforcement for rule-breaking talk and behavior. The Florida results imply that this training accelerates in the environments where it can be rehearsed and rewarded most consistently — the structured but only partially supervised social spaces of the school day and its surrounding routines. They also align with research on unstructured socializing, which finds that unsupervised time with peers is a robust situational trigger for delinquency, and with studies showing that school-adjacent settings shape patterns of adolescent alcohol and marijuana use. The virtual substitutes adolescents relied on during remote schooling — messaging, social media, gaming — appear to have sustained friendships but not to have replicated the intensity of in-person reinforcement, consistent with emerging evidence that online and offline peer influences operate differently.

The study is not without limitations, and the authors are candid about them. The data are cross-sectional, which constrains causal inference; perceived friends’ use may partly reflect projection, the well-documented tendency of adolescents to assume their friends behave as they do. The marijuana measure did not separately capture edible forms of the drug. And because the sample is statewide rather than nationally representative, generalization requires caution. Nevertheless, the pandemic-generated variation in school return timing offers a form of leverage that ordinary survey designs rarely achieve, and the consistency of the moderation result across estimation strategies strengthens confidence in the core conclusion.

The practical implications reach beyond criminology into public health and school policy. Prevention programs have traditionally targeted individual adolescents — educating them about drug risks, building refusal skills, strengthening self-control. The Florida study suggests that such individual-level interventions, while valuable, miss a structural layer: the social settings through which marijuana-using friends exert their influence. Schools, in this framing, are not merely backdrops but active organizers of peer exposure. Prevention efforts, the authors argue, may benefit from extending into the social environments where in-person interactions with marijuana-using peers occur — the rhythms of the school day, the transitions between classes, the informal gatherings before and after instruction — with particular attention to students who report multiple friends who use marijuana. As districts worldwide continue to weigh the costs and benefits of remote, hybrid, and in-person instruction, the study adds an unexpected variable to the calculus: the timing of a school’s reopening may shape not only learning loss and mental health, but the very social channels through which adolescent substance use spreads.

Subject of Research: How variation in school return timing during the COVID-19 pandemic moderated the association between deviant peer association and adolescent marijuana use.

Article Title: Structural Context, Deviant Peer Association, and Adolescent Marijuana Use: Evidence from Variation in School Return Timing during the Pandemic

Article References: Jin, B., & Lanza-Kaduce, L. (2026). Structural Context, Deviant Peer Association, and Adolescent Marijuana Use: Evidence from Variation in School Return Timing during the Pandemic. American Journal of Criminal Justice. https://doi.org/10.1007/s12103-026-09947-7

Image Credits: AI Generated

DOI: 10.1007/s12103-026-09947-7

Keywords: adolescent marijuana use, peer influence, differential association, social learning theory, school return timing, COVID-19, Florida Youth Substance Abuse Survey, criminology, substance use prevention, deviant peers, Structural, Context

Prosocial behavior refers to intentional actions that benefit someone else, whether or not the person helping receives an external reward. In school settings, it can include cooperating with classmates, offering support, sharing resources, defending someone who is being mistreated, or performing small favors for friends and family. Empathy is not a single ability. It includes cognitive processes, such as taking another person’s perspective and understanding what they may be feeling, as well as affective processes involving emotional responsiveness to another person’s condition. The distinction matters because recognizing distress does not automatically lead to assistance. In some circumstances, another person’s suffering can generate self-focused personal distress and avoidance instead of constructive action. Gratitude may help redirect attention outward by highlighting the benefits people receive from others and the value of their relationships. In that sense, the emotion could provide a motivational bridge between noticing another person’s needs and choosing to respond.

To investigate this proposed pathway, the researchers used a quantitative, cross-sectional, correlational design. The sample included 159 students from public schools and 159 from private schools, all between 12 and 16 years old. The average age was 13.2 years, with a standard deviation of 1.5 years. The public-school participants were classified within a low socioeconomic group, while the private-school participants were classified within a middle socioeconomic group using information that included residential stratum, family income, parental education, and occupational stability. Students completed questionnaires in their classrooms during four consecutive weeks of the 2024 academic calendar. Trained research assistants administered the instruments to groups of approximately 20 to 30 students, using standardized instructions and emphasizing voluntary participation, anonymity, and honest responses. The complete session lasted about 25 to 30 minutes. Participation required student assent and written consent from parents or legal guardians, and the fieldwork was reviewed as a no-risk project by Corporación Universitaria Rafael Núñez in Colombia.

The measures were designed to capture different parts of the proposed model. Prosocial behavior was assessed with a 27-item scale covering actions directed toward strangers, friends, and family members. Each category contained nine items rated from one, meaning “not at all like me,” to five, meaning “very much like me.” Empathy was measured with a 15-item Spanish questionnaire for children and early adolescents. Its dimensions included empathic action, perspective taking, emotional contagion, awareness of others, and emotional regulation, with responses recorded on a four-point scale from never to always. Gratitude was assessed with a six-item scale measuring a general tendency to recognize and feel thankful for benefits received from others, using responses from strongly disagree to strongly agree on a seven-point scale. Earlier validation work cited in the study reported acceptable reliability for these instruments in Latin American and Colombian youth, including McDonald’s omega values of .70 to .78 for the empathy dimensions and .75 to .91 for the prosocial behavior dimensions.

The central analysis used structural equation modeling, a statistical technique that allows researchers to estimate relationships among latent constructs that cannot be observed directly. Instead of treating empathy, gratitude, or prosociality as single raw scores, the approach uses patterns across questionnaire items to estimate the underlying variables and then tests pathways between them. The researchers examined whether empathy predicted gratitude, whether both were associated with prosocial behavior, and whether gratitude mediated the relationship between empathy and helping actions. They also conducted multigroup analyses to determine whether the measurement instruments and proposed relationships operated similarly in public and private schools. Measurement invariance is important in this context: before comparing groups, researchers must establish that students in each setting interpret the scales in sufficiently comparable ways. The study reported configural, metric, and scalar invariance for the instruments, indicating that the basic factor structure, factor loadings, and item intercepts were comparable across the two school groups.

The results supported the broad proposed relationship, but its strength varied according to whom students were helping. The model for prosocial behavior toward family members explained 12 percent of the variance, while the model for behavior toward friends explained 42 percent and the model for behavior toward strangers explained 23 percent. These values indicate that empathy and gratitude accounted for a meaningful, but incomplete, share of differences in students’ reported behavior. The model involving friends showed acceptable fit for both groups, with a comparative fit index of .93 in private schools and .84 in public schools, although the root mean square error of approximation was higher for public-school students. The family model showed weaker fit in the public-school group, including a comparative fit index of .73 and an RMSEA of .11. The stranger model also showed weaker fit for public-school students, with a comparative fit index of .77 and an RMSEA of .13. Such values caution against treating the proposed model as a complete explanation of adolescent prosociality.

One of the clearest group differences concerned behavior toward unfamiliar people. Students in public schools scored lower than private-school students on perspective taking, with a small effect size of Cohen’s d = 0.32, and on prosocial behavior toward friends, with a moderate effect size of d = 0.55. The study reported that the empathy–gratitude relationship did not predict helping strangers in the same way in the two groups, and that the public-school model produced a negative predictive value for this outcome. The researchers interpret this pattern in light of the social environments represented in the sample, including socioeconomic vulnerability, insecurity, distrust, and stronger orientation toward close relational networks. In circumstances where social risk is perceived as high, helping a stranger may carry different meanings or costs than helping a family member or friend. Empathy and gratitude may still encourage solidarity, but that solidarity could be directed primarily toward people regarded as trusted or familiar. The finding therefore does not show that public-school students lack empathy or gratitude, nor that they are generally less prosocial.

The study’s cross-sectional design also limits what can be concluded. Because all measures were collected at one point in time, the results demonstrate associations rather than causation. They cannot establish that empathy produces gratitude, that gratitude produces helping, or that a school program designed around either quality would necessarily increase prosocial behavior. It is also possible that students who regularly help others develop greater empathy and gratitude through those experiences, creating a reciprocal developmental process. The authors note that some structural models had fit indices below conventional recommendations and call for more flexible models and additional contextual variables. Future studies could examine school climate, perceived safety, parenting practices, social support, sense of belonging, emotion regulation, and community conditions. Longitudinal research would be particularly valuable because it could track how emotional skills and prosocial actions change across adolescence and whether improvements in one precede changes in the other.

Despite these qualifications, the findings offer a practical direction for education systems seeking to promote supportive school climates. Programs could combine perspective-taking exercises with opportunities for students to recognize assistance, express appreciation, and connect gratitude with concrete cooperative actions. The results suggest that such efforts may be relevant in both public and private schools, while also indicating that the social context must shape how activities are designed. In schools serving communities affected by insecurity or economic strain, building trust and safety may be necessary before encouraging students to extend helping behavior beyond immediate relationships. The researchers conclude that empathy and gratitude are consistent predictors of prosociality across the school contexts studied, especially toward family and friends. Their work does not reduce kindness to two psychological traits, but it identifies a potentially important mechanism through which emotional understanding can become social action—and shows why that mechanism must be examined within the real environments where young people live and learn.

The study’s comparison across school types is scientifically important because socioeconomic context can affect not only behavior itself but also how students interpret questionnaire items. Configural invariance indicates that the same broad pattern of dimensions was present in both groups; metric invariance supports comparing associations among those dimensions; and scalar invariance permits comparisons of average latent scores. Together, these tests strengthen the basis for group comparisons, although they do not eliminate differences in lived experience or guarantee that every item carries precisely the same practical meaning for every student.

The mediation result is best understood as a proposed statistical pathway rather than a confirmed sequence of psychological events. In a cross-sectional model, students who report greater empathy may also report greater gratitude and prosociality, but the data cannot determine whether gratitude develops afterward, whether helping experiences cultivate both qualities, or whether another factor influences all three. This distinction matters for intervention design. School programs can reasonably use the findings to test activities that connect perspective-taking and appreciation with cooperative behavior, while evaluating outcomes prospectively and monitoring whether effects differ by target of assistance, classroom climate, and perceived safety. Such testing could clarify whether gratitude is a modifiable mechanism or primarily a marker of broader supportive relationships.

Subject of Research: Empathy, gratitude, and prosocial behavior among Colombian school students

Article Title: Study on the prediction of prosociality through empathy and gratitude in the school context of Cartagena de Indias, Colombia

Article References: Tezón, M. I. (2026). Study on the prediction of prosociality through empathy and gratitude in the school context of Cartagena de Indias, Colombia. Journal of New Approaches in Educational Research, 15(1), Article 24. https://doi.org/10.1007/s44322-026-00054-3

Image Credits: AI Generated

DOI: 10.1007/s44322-026-00054-3

Keywords: empathy, gratitude, prosocial behavior, adolescent development, school psychology, Colombia, structural equation modeling, social-emotional learning, prediction, prosociality, school, context

Mycorrhizae are symbiotic associations between fungi and plant roots. The fungi extend microscopic filaments, known as hyphae, through the soil, effectively increasing the root system’s reach. In exchange for carbon compounds produced through photosynthesis, the fungi can improve access to phosphorus, nitrogen, water and micronutrients. The relationship may also influence plant health by affecting pathogens, soil structure and interactions with other microorganisms. Most land plants form some type of mycorrhizal association, but the identity, strength and ecological consequences of those partnerships vary widely.

The new work focuses on how these associations relate to non-native plants across environmental contexts rather than treating all invasions as ecologically identical. That distinction is crucial because a plant introduced into a dry grassland faces a different set of constraints from one arriving in a tropical forest, temperate woodland or nutrient-poor island ecosystem. Soil chemistry, climate, native vegetation, fungal communities and land-use history can all determine whether a fungal partnership is beneficial, neutral or even costly. The study’s central message is that mycorrhizal strategy must be interpreted geographically and ecologically, not as a fixed trait of “invasive plants.”

One of the most important variables is biome. A biome is defined by broad combinations of climate, vegetation and ecological processes, and each biome supports distinctive communities of soil fungi. In some environments, forming a close association with fungi may help an introduced plant obtain scarce nutrients or tolerate drought. In others, the plant may gain little from the local fungal community, or it may prosper by investing less in symbiosis and more in rapid growth, reproduction or dispersal. This flexibility means that the same plant lineage can encounter very different underground opportunities after crossing a continent or entering a new climatic zone.

Disturbance adds another layer of complexity. Fire, cultivation, grazing, road construction, urbanization and repeated soil disruption can remove vegetation, alter nutrient cycles and break apart established fungal networks. Disturbed ground is often described as a blank slate for invaders, but it is rarely biologically empty. It may contain resilient fungal propagules, newly introduced microbes or a simplified community dominated by organisms adapted to rapid environmental change. Under such conditions, plants with different mycorrhizal requirements may experience contrasting advantages. A disturbance can weaken native plant–fungus partnerships while creating opportunities for non-native plants that are compatible with a broader range of fungi.

The findings therefore complicate the popular “invasive plants bring their own fungi” narrative. Some introduced plants may associate with fungal partners from their original range, a process sometimes called symbiont introduction. Others may recruit native fungi already present in the invaded ecosystem. Still others may shift between fungal partners depending on soil conditions. These pathways can influence establishment, but none should be assumed to dominate everywhere. The ecological outcome may depend on whether the plant’s fungal partners are available, whether they provide meaningful nutritional benefits and whether native plants already occupy the most productive symbiotic networks.

This context is especially important for predicting biological invasions. Management strategies sometimes treat mycorrhizal fungi as a single lever: remove them, add them or manipulate them to control plant spread. The study suggests that such interventions could produce inconsistent results. Suppressing fungal activity might hinder a non-native plant in one habitat but have little effect in another, particularly if the plant can switch partners or grow effectively without a strong symbiosis. Conversely, introducing beneficial fungi to support restoration could unintentionally assist non-native species if the ecological conditions favor them. Effective management will require information about local fungal communities, disturbance history and the specific mycorrhizal biology of both native and introduced plants.

The research also carries a broader warning about how ecological traits are used in large-scale analyses. Labels such as “mycorrhizal” or “non-mycorrhizal” compress a dynamic relationship into a simple category, even though fungal associations can change with plant age, soil fertility, season and climate. A plant may form abundant fungal connections but receive limited nutritional benefit, while another may depend heavily on fungi despite showing a less visible association. Future invasion forecasts may become more accurate when they incorporate the flexibility of these partnerships, the distribution of fungal symbionts and the ways global change is reshaping disturbance patterns. The underground biology of invasion is not a single story repeated worldwide; it is a shifting interaction between plants, fungi and place.

By showing that the mycorrhizal strategy of non-native plants varies with biome and disturbance, Cazzaniga, Lauber, van den Hoogen and colleagues move the debate beyond the idea that one hidden biological advantage explains invasion success. Their work points toward a more conditional model, in which fungal partnerships can help, fail to matter or change direction depending on environmental circumstances. As ecosystems experience intensifying land use, climate disruption and the movement of species across continents, understanding those conditions could become essential. The next generation of invasion science may depend as much on mapping fungal networks beneath the soil as on tracking plants above it.

Subject of Research: Mycorrhizal strategies of non-native plants across different biomes and disturbance regimes.

Article Title: Mycorrhizal strategy of non-native plants varies with biome and disturbance.

Article References: Cazzaniga, S.G., Lauber, T., van den Hoogen, J. et al. “Mycorrhizal strategy of non-native plants varies with biome and disturbance.” Nature Ecology & Evolution (2026). https://doi.org/10.1038/s41559-026-03144-9

Image Credits: AI Generated

DOI: https://doi.org/10.1038/s41559-026-03144-9

Keywords: mycorrhizae, non-native plants, biological invasions, plant–fungus symbiosis, biome, disturbance ecology, soil ecology, invasion biology, ecosystem restoration