Ecological validity of social interaction tests in rats and mice.

Different rat and mouse models are used in studies of social interactions. Simple behavioral measures, which are commonly used in the laboratory, allow to perform relatively short experiments and to use multiple brain manipulation techniques. However, too much focus on the simplest behavioral models generates a serious risk of reducing ecological validity or even studying phenomena which would never happen outside of the laboratory. In this review, we discuss the suitability of mice and rats as model organisms for studying social behaviors, with focus on social transmission of fear paradigms. First, we briefly introduce the concept of domestication and what impact it had on laboratory rodents. Then, we present two aspects of social behaviors, sociability and dominance, which are crucial for social organization in these species. Finally, we present experimental models used for studying how animals transmit information about danger between each other, and how these models may reflect what happens in the natural environment. We discuss the difficulties that arise from our limited knowledge of rat and mouse ecology, especially their social life. We also explore the subject of balancing ecological validity and controllability in rodent models of social behaviors, the latter being particularly important for studying brain activity. Although it is very challenging, an efficient program for social neuroscience research should, in our opinion, aim at bridging the gap between laboratory and field studies.

Modeling the quantitative nature of neurodevelopmental disorders using Collaborative Cross mice.

Background: Animal models for neurodevelopmental disorders (NDD) generally rely on a single genetic mutation on a fixed genetic background. Recent human genetic studies however indicate that a clinical diagnosis with ASDAutism Spectrum Disorder (ASD) is almost always associated with multiple genetic fore- and background changes. The translational value of animal model studies would be greatly enhanced if genetic insults could be studied in a more quantitative framework across genetic backgrounds. Methods: We used the Collaborative Cross (CC), a novel mouse genetic reference population, to investigate the quantitative genetic architecture of mouse behavioral phenotypes commonly used in animal models for NDD. Results: Classical tests of social recognition and grooming phenotypes appeared insufficient for quantitative studies due to genetic dilution and limited heritability. In contrast, digging, locomotor activity, and stereotyped exploratory patterns were characterized by continuous distribution across our CC sample and also mapped to quantitative trait loci containing genes associated with corresponding phenotypes in human populations. Conclusions: These findings show that the CC can move animal model studies beyond comparative single gene-single background designs, and point out which type of behavioral phenotypes are most suitable to quantify the effect of developmental etiologies across multiple genetic backgrounds.

The lost study: a 1998 adoption study of personality that found no genetic relationship between birthparents and their 240 adopted-away biological offspring.

In 1998, Robert Plomin and his Colorado Adoption Project (CAP) colleagues published the results of a longitudinal adoption study of personality. They found an average personality test score correlation of only 0.01 between birthparents and their 240 adopted-away 16-year-old biological offspring, suggesting no genetic influences on personality. However, the researchers interpreted their results in the context of previous twin studies, produced an average 14% heritability estimate, and concluded that nonadditive genetic factors underlie personality traits. The author challenges these conclusions and notes that the near-zero correlation stands in contrast to other types of behavioral genetic methods, such as twin studies, that are more vulnerable to environmental confounds and other biases. The author shows that authoritative psychology texts frequently fail to mention this 1998 CAP study. When it is mentioned, the original researchers' conclusions are usually accepted without critical analysis. The author also assesses the results in the context of the 20-year failure to discover the genes that behavioral geneticists believe underlie personality traits. He concludes that this 1998 investigation is a "lost study" in the sense that, although it is one of the most methodologically sound behavioral genetic studies ever performed, its results are largely unknown.

Epigenetics and its implications for Psychology / La epigenética y sus implicaciones para la Psicología

Background: Epigenetics is changing the widely accepted linear conception of genome function by explaining how environmental and psychological factors regulate the activity of our genome without involving changes in the DNA sequence. Research has identified epigenetic mechanisms mediating between environmental and psychological factors that contribute to normal and abnormal behavioral development. Method: the emerging field of epigenetics as related to psychology is reviewed. Results: the relationship between genes and behavior is reconsidered in terms of epigenetic mechanisms acting after birth and not only prenatally, as traditionally held. Behavioral epigenetics shows that our behavior could have long-term effects on the regulation of the genome function. In addition, epigenetic mechanisms would be related to psychopathology, as in the case of schizophrenia. In the latter case, it would be especially relevant to consider epigenetic factors such as life adversities (trauma, disorganized attachment, etc.) as related to its clinical manifestations, rather than genetic factors. Moreover, epigenetics implies overcoming classical dualist dichotomies such as nature-nurture, genotype-phenotype or pathogenesis-pathoplasty. Conclusions: In general, it can be stated that behavior and environment will finally take on a leading role in human development through epigenetic mechanisms (AU)

La epigenética está cambiando la concepción lineal que se suele tener de la genética al mostrar cómo eventos ambientales y psicológicos regulan la actividad de nuestro genoma sin implicar modificación en la secuencia de ADN. La investigación ha identificado mecanismos epigenéticos que juegan un papel mediador entre eventos ambientales y psicológicos y el desarrollo normal y alterado. Método: el artículo revisa el campo emergente de la epigenética y sus implicaciones para la psicología. Resultados: entre sus implicaciones destacan la reconsideración de la relación entre genes y conducta en términos de procesos epigenéticos que acontecen a lo largo de la vida y no solo prenatalmente como se asumía. La epigenética conductual muestra que nuestra conducta puede tener efectos a largo plazo sobre la función genómica. Otra implicación concierne a la psicopatología, señaladamente a la esquizofrenia. Más que de causas genéticas, habría que hablar de mediadores epigenéticos entre las adversidades de la vida (trauma, apego desorganizado) y formas clínicas. Asimismo, la epigenética implica la superación de dicotomías dualistas como herencia-medio, genotipo-fenotipo y patogenia-patoplastia. Conclusiones: en general, se puede decir que la conducta y el ambiente asumirán finalmente un papel protagonista en el desarrollo humano mediante mecanismos epigenéticos (AU)

Insatisfacción corporal en la adolescencia: Evolución en una década / Body dissatisfaction in adolescence. Changes in a decade

La presente investigación examina los cambios en la imagen corporal y en el índice de masa corporal ocurridos en un periodo de 11 años en una muestra de adolescentes españoles con edades comprendidas entre los 13 y 21 años. Los datos provienen de dos submuestras recogidas en el año 1997 (n = 3468) y en el año 2008 (n = 846). La imagen corporal fue operacionalizada por medio de la escala insatisfacción corporal perteneciente al inventario de trastornos de la conducta alimentaria (Garner, 1998, 2004). Los resultados pusieron de manifiesto que el índice de masa corporal es una covariable importante en el estudio de la insatisfacción corporal. Se observó una disminución no-significativa de los valores medios de insatisfacción corporal en la muestra de mujeres. Las puntuaciones de los varones no han cambiado durante los últimos 11 años (AU)

This study examines the changes in adolescents’ body image and body mass index over the last 11 years. Data came from two different subsamples collected in the years 1997 (n = 3468) and 2008 (n = 846). The body image was assessed by the Body Dissatisfaction scale belonging to Eating Disorder Inventory (Garner, 1998, 2004). The results showed that the Body Mass Index is an important covariable in the study of the body dissatisfaction. The body dissatisfaction mean values decreased in the female sample, although the observed reduction was not statistically significant. The male’s values didn’t change over the last 11 years (AU)

The standardization-generalization dilemma: a way out.

Recently, a debate has emerged on the use and necessity of standardization in experimental testing using animal subjects. The difficulties encountered when trying to reconcile standardization and generalization largely underlie this debate. The more specific the testing procedures are, the less one can generalize to more naturalistic situations, including to human clinical populations. If the goal of a study is to generalize to a larger population, there may be a higher risk attached to false-positive than false-negative results; thus the balance sways toward generalization. Heterogenization of housing conditions and of genetic makeup of experimental animals has been suggested as a possible method to increase the generalizability of results. It is important to remain cognizant, however, of situations in which false negatives can be counterproductive or even dangerous, such as when the goal is to elucidate a physiological mechanism, when expected effect sizes are small, in toxicological studies and in drug safety testing. In such cases, experiments based on standardization may provide more useful information. We pose that it is essential that the goal of the specific experiment conducted is clearly defined and that the decision to balance between standardization and generalization must be made based on the specific needs to meet the intended goal. In this light, we discuss a multi-tiered approach to animal experimentation, in which standardization and generalizability are each given precedence during different phases of a project, depending upon the goal of the experiment.

Better never than late: peer review and the preservation of prejudice.

This article documents some difficulties authors face who challenge faulty research claims published in mainstream literature. Editors of "reputable journals" may react with stonewalling tactics that tend to enshrine these faulty results. A case in point is the mental test literature, which has long been beset with racist myths. In 1985, Arthur Jensen added a new myth, his "Spearman Hypothesis," which asserts that a positive correlation between White/Black means differences in scores on mental tests and the loadings of the first principal component confirms the existence of a general intelligence factor ("g"). It can be shown by mathematical and geometric deduction, by computer stimulation, and by reference to "real data," including Jensen's own, that the assertion is unwarranted, and that the relationship Jensen observed is an artifact that has nothing to do with ethnicity or "g." Nevertheless, it proved impossible for more than 12 years to record this challenge to Jensen's claims in any of the leading journals in psychology and statistics. Typically, their editors invoked arguments having nothing to do with the fundamental question of whether Jensen's claims are true or false. It is concluded that, in view of the transparent racist implications of these claims, such editorial policies--regardless of their motivations--contribute to the preservation of ethnic stereotypes and prejudice.

La comprensión infantil de la actividad prescriptiva de la autoridad / Children's understanding of authority's prescriptions

Se presentan algunos resultados de investigación acerca del modo en que sujetos de 7 a 14 años conciben la actividad prescriptiva de una autoridad política y otra escolar. El análisis de los datos intenta mostrar cómo se va transformando el pensamiento infantil desde una concepción personalizada acerca de la actividad prescriptiva de la autoridad hacia la inclusión de dicha actividad en un sistema de relaciones normativas. Respecto de las dos autoridades, los niños menos avanzados sostienen que el mando se produce de modo directo. En un segundo momento, los sujetos afirman que la actividad de prescribir involucra la elaboración de reglas, normas o leyes. Los más avanzados conciben que la autoridad no sólo produce reglas, sino que está subordinada a un sistema normativo que regula su propia actividad. Si bien la secuencia de ideas acerca de ambas autoridades guarda semejanza, aparecen desfases en el desarrollo.

Some investigation results about the way in that subjects of 7 to 14 years conceive the prescriptive activity of a political authority and another school one, are presented. The analysis of the data tries to show how the childish thought is been transformed from a personalised conception about the prescriptive activity of the authority toward the inclusion of this activity in a system of normative relationships. Regarding the two authorities, the less advanced children sustain that the commandment takes place in a direct way. In a second moment, the fellows affirm that the activity of prescribing involves the elaboration of rules, norms or laws. The most advanced conceive that the authority not only produces rules, but it is also subordinated to a normative system that regulates its own activity. Although the sequences of both authorities' ideas keeps likeness, "décalages" appears in the development.