PSI Tesis doctorado

Permanent URI for this collection

Browse

Recent Submissions

Now showing 1 - 5 of 77
  • Item
    Diderencias de género en los mecanismos explicativos de los cambios en la conducta delictiva de hombres y mujeres infractores de ley
    (2024) Condemarín Norambuena, Carolina; Carvacho García, Héctor; Pontificia Universidad Católica de Chile. Escuela de Psicología
  • Item
    Comparative Analysis of Etiological models of Adolescent substance use
    (2025) Soto Martínez, Marcela I.; Vergés, Álvaro; Pontificia Universidad Católica de Chile. Escuela de Psicología
    Drug use is a mental health concern with serious physical and psychological consequences, which are especially critical during adolescence. In Chile, approximately 20% of adolescents report alcohol or marijuana use during the last year. For both substances, prevalence is higher among females (alcohol: 26%, cannabis: 21%) than males (alcohol: 20%, cannabis: 17%). Use increases with grade level—from 11% (alcohol) and 10% (cannabis) in eighth grade to 36% and 27%, respectively, by the final year of high school. Additionally, students attending private schools report higher alcohol use (30%) but lower cannabis use (14%) compared to those from other school types.To explain individual differences in substance use patterns, several mediational models have been proposed, focusing on the role of cognitive variables in the relationship between impulsivity and substance use. Two key models in this field are the Acquired Preparedness Model (Smith & Anderson, 2001) and the 3-Component Approach to Reinforcing Substances (3-CARS; Gullo et al., 2010).This study aimed to test and compare the APM and 3-CARS as etiological models of substance use behaviors in adolescence. To this end, three studies were conducted: (1) a systematic review of the literature on impulsivity, expectancies, and substance use in adolescents; (2) an evaluation of the psychometric properties of the Cannabis Refusal Self-Efficacy Scale; and (3) an empirical comparison of the APM and 3-CARS in a Chilean adolescent sample.The systematic review included 17 studies, 23 models, and 123 mediations, focused exclusively on alcohol and tobacco. Few studies used longitudinal designs (n = 4) or probabilistic sampling (n = 7). The most frequently examined impulsivity-related constructs and mediators were sensation seeking (n = 47), impulsivity (n = 31), reward drive (n = 18), positive social expectancies (n = 28), coping motives (n = 28), and refusal self-efficacy (n = 26). Of all mediations analyzed, only 37.6% were statistically significant (n = 50), whereas over half of the direct effects were significant.The validation of the Cannabis Refusal Self-Efficacy Scale yielded good model fit: χ²(74) = 245.662, p < .000, CFI = .974, TLI = .969, RMSEA = .047, SRMR = .029. Psychometric indicators were strong, with factor loadings ranging from .65 to .94, reliability coefficients from ω = .64 to .95, and temporal stability (ICC) between .78 and .88. As expected, the scale was significantly correlated with marijuana use frequency, problems, and reinforcement sensitivity. Scalar invariance was established across sex, age, and problematic use levels, enabling meaningful group comparisons.In the final empirical study, four models were estimated (2 theoretical models × 2 substances: alcohol and cannabis), all showing good fit. The 3-CARS models explained more variance in problematic cannabis use, and included a greater proportion of significant direct effects than the APM. Across all models, positive expectancies emerged as the only consistent significant mediator. The only model in which no significant indirect effects were found was the 3-CARS model predicting cannabis-related problems.This study is the first to compare the APM and 3-CARS models and to evaluate their predictive capacity for cannabis-related outcomes. Reward drive and sensation seeking—identified as significant mediators in the empirical analysis—were also the most frequently studied impulsivity constructs in the systematic review. Positive expectancies consistently emerged as a key mediator, supported by both theoretical and empirical evidence. Finally, theoretical and practical implications are discussed.
  • Item
    Trayectorias de cambio en variables psicológicas predictoras del rendimiento académico en educación terciaria
    (2024) Armijo R., Iván; Manzi Astudillo, Jorge; Pontificia Universidad Católica de Chile . Facultad de Ciencias Sociales
    El National Research Council en Estados Unidos publicó un modelo en el año 2012 que sintetiza las habilidades y destrezas necesarias para el éxito académico y laboral, diferenciando 3 dominios de competencia (cognitivo, interpersonal e intrapersonal) y un conjunto de habilidades (Inteligencia fluida, Inteligencia cristalizada, habilidad amplia de recuperación de información) y rasgos centrales (extroversión y afabilidad en lo interpersonal; prolijidad, estabilidad y apertura en lo intrapersonal) que movilizan las competencias dentro de esos tres dominios. Este estudio buscó identificar la existencia de perfiles que agrupen a los estudiantes en base a la combinación de esas habilidades y rasgos centrales y establecer la relación que tienen con variables de rendimiento, involucramiento, autoeficacia y autopromoción académica, y determinar las diferencias que existen entre estudiantes de distintos tipos de institución y con distintos niveles de tiempo dentro de educación superior. Además, busca identificar patrones de cambio en el tiempo de las variables mencionadas, tanto en forma individual como agrupadas en perfiles. Se trabajó con una muestra amplia de estudiante de Instituto Profesional (IP) y de universidad, los cuales fueron medidos en la variables señaladas haciendo uno o dos seguimientos. Se aplicó un análisis de perfiles latente para identificar los distintos subgrupos de estudiantes en la primera medición, separados por institución y cohorte de tiempo, análisis de crecimiento latente y pruebas t para identificar los cambios en el tiempo y análisis SEM para verificar las relaciones entre las distintas variables y su impacto en rendimiento. Se encontraron dos tipos de perfiles que combinan niveles comparativamente altos en habilidades cognitivas y bajos en rasgos inter o intrapersonales que están presentes en ambos tipos de institución y en las distintas cohortes de tiempo. La diferencias principal entre perfiles de IP y Universidad viene dada en que mientras en IP la discriminación entre perfiles se centra en lo cognitivo, en las universidades incluye también aspectos intra e interpersonales. Además, en estudiantes de primer año aparece un tercer perfil que mezcla distintos aspectos de los otros dos, pero que desaparece en las cohortes mayores y que se asocia a peores índices de rendimiento. En cuanto a los patrones de cambio, no se detectaron cambios significativos en el tiempo salvo en aspectos puntuales, aunque si un efecto positivo de retorno a la presencialidad en quienes ingresaron en pandemia. A nivel de modelo genera, se verificó el impacto del dominio cognitivo, el involucramiento con la carrera y la institución y la autopromoción sobre el logro de mejores índices de rendimiento.
  • Item
    Women are warm, but she isn’t: how and when gender stereotypes are applied
    (2025) Paz Martín, Sarah; Cumsille E., Patricio; Pontificia Universidad Católica de Chile. Escuela de Psicología
    This dissertation aimed to disentangle the psychological mechanisms and conditions underlying the application of gender stereotypes. Specifically, it sought to test the distinction between the activation and application of gender stereotypes, evaluate the effect of counterstereotypical examples on stereotype application, identify whether stereotype activation functions as a mechanism through which stereotype application operates, and assess the effect of individual factors on the activation and application of gender stereotypes. These objectives were addressed through three experiments and a measure validation study. The first study, comprising two experiments, established the empirical distinction between stereotype activation and application. We adapted and validated a single experimental task that addresses both processes and separates them using formal modeling techniques. The second study validated a sexism measure in a separate sample from the same population, which was then used to evaluate its role as an individual factor influencing stereotype activation and application. The final study, involving one experiment, examined the effect of counter-stereotypical examples on stereotype application. We evaluated the mediating role of stereotype activation and the influence of individual factors such as sexism, motivation to respond without sexism and gender essentialism. Our findings enhance the understanding of how and when gender stereotypes are applied, shedding light on the cognitive processes involved in forming impressions of both stereotypical and counter-stereotypical individuals. These insights are crucial for developing more effective strategies to mitigate the negative impact of harmful gender stereotypes.
  • Item
    Pilot RCT and implementation study of a preventive sexual and mental health program for high school students. A mixed method research of a gendertransformative intervention
    (2025) Torres Cortés, Betzabé; Olhaberry Huber, Marcia; Pontificia Universidad Católica de Chile. Escuela de Psicología; Pontificia Universidad Católica de Chile. Departamento de Psicología
    Sexuality is a crucial aspect of individuals' lives, particularly during adolescence, when young people face challenges that require preventive interventions. Sexuality education programs are among the most widely used strategies to promote sexual health among adolescents. However, there is significant variability in the components of these interventions. On the other hand, comprehensive sexuality education (CSE) programs have the strongest evidence of effectiveness. Yet, many of these programs fail to adequately address gender-related issues and mental health, limiting their potential to benefit all adolescents and contributing to health inequities. Therefore, the aim of this doctoral thesis is twofold: (i) to design a gender-transformative and comprehensive sex education program for public high school students, and (ii) to evaluate the acceptability, feasibility (through a pilot randomized controlled trial), and implementation of the program, contributing to a broader evaluation of the intervention and explaining how its implementation influences gender equity in health. A mixed-methods experimental design was used across four phases: (1) program design, (2) pilot randomized controlled trial (RCT), (3) case study, and (4) integration. A total of 179 students from four public high schools were randomly assigned to either the experimental or control group. The experimental group received "Enfócate," a comprehensive, gender-transformative sexuality education program. The case study phase involved 4 individual interviews and 8 focus groups with participants from the experimental group. The second phase of the study demonstrated that the intervention was feasible and had adequate levels of acceptability. Additionally, no statistically significant differences were observed between pre- and post-intervention assessments in the experimental group compared to the control group. However, the case study revealed that both students and providers identified learning outcomes that were not captured by the assessment tools. The case study also highlighted various factors related to the program’s implementation that contributed to promoting health equity. Finally, the integration presented in the discussion section addresses the reasons for the discrepancies between the results of the different phases of the study and offers conclusions on how to ensure the acceptability, feasibility, and promotion of health equity in such interventions.