Twin study on metacognition and its related symptoms

Project lead: Prof. Simona Scaini PhD (simona.scaini@mail.sfu.ac.at)
Project member: Stefano De Francesco, MSc

The research project will involve the collection and use of exclusively quantitative data from a general-population, non-clinical sample of twins. The twin method compares monozygotic twins, born from a single zygote, hence genetically identical, with dizygotic twins, which are born from two separate fertilized eggs and share only 50% of the genetic heritage. Genetic and environmental contributions are predicted by means of correlation coefficients, through which it is possible to obtain a direct estimate of variance and covariance among traits.

In the present project, parents of about 1750 twin pairs aged 8-17 years, including both those previously enrolled in the Italian Twin Registry (ITR) and those who will be enrolled specifically for this project, will be contacted and invited to take part to the study. Parents and children who will give their consent for the participation will be asked to fill out specific questionnaires for the evaluation of metacognitive beliefs, internalizing and externalizing symptoms and personality traits.

More specifically, in order to obtain information concerning children’s metacognitive beliefs and the personality traits believed to be associated with them three questionnaires will be administered directly to the twin pairs, namely the Metacognitions Questionnaire for Children (MCQ-C; Bacow et al., 2009), the Barratt Impulsiveness Scale-11, Adolescent Version (BIS-11-A; Fossati et al., 2002) and the Neuroticism subscale of the Junior Eysenck Personality Questionnaire-Revised (JEPQR-A; Colledani et al., 2018). First, correlation coefficients between the MCQ-C scores and JEPQR-A and BIS-11-A scores will be estimated to confirm convergent validity of MCQ-C questionnaire.

Subsequently, correlations between different variables for individual twins (‘phenotypic’ correlations) and between twins within pairs either for the same variable (‘cross-twin/within-trait’ correlations) or for different variables (‘cross-twin/cross-trait’ correlations) will be calculated and interpreted under the assumption of the twin study design. Then quantitative-genetics twin models will be applied to data with the aim to investigate the possible causes of variation and covariation between phenotypes, as well as the mechanisms of intergenerational transmission of metacognitive beliefs.

The sample will be divided into two age groups: one between 8 and 12 years old, and the other between 13 and 18 years old. Multivariate models will be fitted separately to the two age groups, and the best-fitting model in each age group will be detected.

In the light of what has been reported, the present research sets three specific aims:

1) to estimate the heritability of metacognition, shedding light on the latent factors that contribute to the intergenerational transmission of metacognitive beliefs;
2) to investigate the common etiological factors that might be responsible for the association of dysfunctional metacognition with internalizing and externalizing features, analyzing the genetic and environmental contributions to the covariance between metacognitive beliefs, internalizing and externalizing traits at the same time. In this way, it would be possible to verify if and to what extent the etiological factors at the basis of dysfunctional metacognitive processes overlap with those responsible for the co-occurrence between symptoms in both the aforementioned diagnostic clusters;
3) to test for potential age-related differences in the structure of factors at the basis of the covariance between the phenotypes analyzed.

In metacognitive processes, as theorized by Wells and Matthews, executive functions are involved, which are known to undergo changes in the transition from childhood to adolescence. During childhood, for example, there is neural immaturity at the level of the prefrontal cortex, which implies that during this period, cognitive processes (e.g., inhibition, updating, and shifting) cannot be distinguished and are all linked to a common process. In adolescence, instead, the increasing neural development causes this common executive function to specialize into separate processes. This finding makes it reasonable to hypothesize that a greater influence of genetic factors on metacognitive processes could be found in adolescence than in childhood.

Such a pattern would be in line with that shown by several twin studies in relation to internalizing and externalizing symptoms. These studies, in fact, have pointed out that the contribution of genetic factors to the comorbidity bond between internalizing and externalizing features becomes more and more significant as individuals transition from childhood to adolescence. Results on this topic could be undoubtably useful in shedding light on the phenotypic nature of the p factor, supporting the idea that there might be dysfunctional metacognitive thoughts at the basis of symptoms belonging to both diagnostic clusters.

Shedding light on the role that metacognition may play within the frequent dynamic of co-occurrence between internalizing and externalizing disorders as a phenotypic manifestation of the p factor, would offer researchers and clinicians insightful indications about the possible causes for the onset of mental disorders, which are highly valued in psychopathological symptomatology epidemiological questions. Identifying risk factors predicting psychopathology development and persistence would provide scholars the opportunity to hypothesize and promote preventive interventions.

Investigating the etiological factors at the basis of dysfunctional metacognitive processes and of their association with internalizing and externalizing features could be undoubtably useful both to plan effective prevention strategies and to guide clinicians in choosing the best intervention possible; this is in line with the idea of considering Metacognitive Therapy (MCT; Wells, 2009), even at young age, as a promising strategy in the treatment of not only of persistent internalizing, but also externalizing symptoms.

In addition, investigating heritability and intergenerational transmission could help in understanding key acquisition mechanisms and could encourage acting on them for example by parent-training strategies.

This project is funded by the Austrian Science Fund (FWF).

Project start: 15th Sept. 2024
Project duration: 36 months