Land grabbing in Latin America and the Caribbean

Land grabbing has gained momentum in Latin America and the Caribbean during the past decade. The phenomenon has taken different forms and character as compared to processes that occur in other regions of the world, especially Africa. It puts into question some of the assumptions in the emerging literature on land grabbing, suggesting these are too food-centered/too food crisis-centered, too land-centred, too centred on new global food regime players – China, South Korea, Gulf States and India – and too centred on Africa. There are four key mechanisms through which land grabbing in Latin American and the Caribbean has been carried out: food security initiatives, energy/fuel security ventures, other climate change mitigation strategies, and recent demands for resources from newer hubs of global capital. The hallmark of land grabbing in the region is its intra-regional character: the key investors are (Trans-)Latin American companies, often in alliance with international capital and the central state. Initial evidence suggests that recent land investments have consolidated the earlier trend away from (re)distributive land policies in most countries in the region, and are likely to result in widespread reconcentration of land and capital.     

Examining Multiracial Youth in Context: Ethnic Identity Development and Mental Health Outcomes

Although multiracial individuals are the fastest growing population in the United States, research on the identity development of multiracial adolescents remains scant. This study explores the relationship between ethnic identity, its components (affirmation, exploration), and mental health outcomes (anxiety, depressive symptoms) within the contexts of schools for multiracial adolescents. The participants were multiracial and monoracial minority and majority high school students (n = 4,766; 54.6 % female). Among the participants, 88.1 % were Caucasian, 7.4 % were African American, and 4.5 % were multiracial. The research questions examined the relationship between ethnic identity exploration and affirmation on mental health outcomes and explored the role school context plays in this relationship. The findings suggested that multiracial youth experience more exploration and less affirmation than African Americans, but more than Caucasians. In addition, multiracial youth were found to have higher levels of mental health issues than their monoracial minority and majority peers. Specifically, multiracial youth had higher levels of depressive symptoms than their African American and Caucasian counterparts. Multiracial and Caucasian youth had similar levels of anxiety but these levels were significantly higher than African Americans. School diversity did not influence mental health outcomes for multiracial youth. These findings provide insight into the experiences of multiracial youth and underscore the importance of further investigating factors that contribute to their mental health outcomes.     

Rethinking Timing of First Sex and Delinquency

The relation between timing of first sex and later delinquency was examined using a genetically informed sample of 534 same-sex twin pairs from the National Longitudinal Study of Adolescent Health, who were assessed at three time points over a 7-year interval. Genetic and environmental differences between families were found to account for the association between earlier age at first sex and increases in delinquency. After controlling for these genetic and environmental confounds using a quasi-experimental design, earlier age at first sex predicted lower levels of delinquency in early adulthood. The current study is contrasted with previous research with non-genetically informative samples, including Armour and Haynie (2007, Journal of Youth and Adolescence, 36, 141–152). Results suggest a more nuanced perspective on the meaning and consequences of adolescent sexuality than is commonly put forth in the literature.

TrueAllele® Genotype Identification on DNA Mixtures Containing up to Five Unknown Contributors

Computer methods have been developed for mathematically interpreting mixed and low‐template DNA. The genotype modeling approach computationally separates out the contributors to a mixture, with uncertainty represented through probability. Comparison of inferred genotypes calculates a likelihood ratio (LR), which measures identification information. This study statistically examined the genotype modeling performance of Cybergenetics TrueAllele^® computer system. High‐ and low‐template DNA mixtures of known randomized composition containing 2, 3, 4, and 5 contributors were tested. Sensitivity, specificity, and reproducibility were established through LR quantification in each of these eight groups. Covariance analysis found LR behavior to be relatively invariant to DNA amount or contributor number. Analysis of variance found that consistent solutions were produced, once a sufficient number of contributors were considered. This study demonstrates the reliability of TrueAllele interpretation on complex DNA mixtures of representative casework composition. The results can help predict an information outcome for a DNA mixture analysis.     

Parent-adolescent congruence for adolescent substance use

Parental reports of adolescent substance use were compared to the adolescents' self-reports using identical scales. Congruence was defined as exact agreement on whether adolescents were current users, ex-users, or never-users. Both parents were found to be less accurate in predicting their adolescents' alcohol use compared to cigarette or marijuana use. Single mothers were significantly less likely to be congruent than were mothers from two-parent households. Mother and father congruence on all substances was unrelated to the adolescent's sex, race, or after school employment. For both parents, congruence for adolescent marijuana use was significantly related to the age and GPA of the adolescent. Congruence may also reflect important properties of family functioning, as significant relations were found between both adolescent and parent ratings of family cohesion and parent-adolescent congruence on perceptions of marijuana use.This research was supported by Grant DA03706 from the National Institute of Drug Abuse (Hyman Hops, Principal Investigator).Jennifer Langhinrichsen is a doctoral candidate in psychology interested in adolescent and family interactions. The other authors are psychologists or data analysts working on family influences on substance use and mental health.     

First-Year College Student Affect and Alcohol Use: Paradoxical Within- and Between-Person Associations

Based on 10 weekly telephone interviews with first-year college students (N=202; 63% women; M=18.8 years, SD=.4), within- and between-person associations of positive and negative affect with alcohol use were examined. Multi-level models confirmed hypothesized within-person associations between weekly positive affect and alcohol use: Higher positive affect weeks had greater alcohol consumption, more drinking and heavy drinking days in the same week, and less plans to drink the following week. However, between-person, average positive affect did not predict individual differences in alcohol use. The negative affect—alcohol use association was complex: Within-person, higher negative affect was associated with less drinking days but between-person, with more drinking days; lability in negative affect was associated with greater average alcohol use and more drinking and heavy drinking days. Health promotion efforts for late adolescent and emerging adult students are advised to recognize these paradoxical effects (e.g., promoting dry celebratory campus-events, strategies to manage negative mood swings).