Free Will, Determinism, and Intuitive Judgments About the Heritability of Behavior

Asymmetric genetic attributions for one's own prosocial versus antisocial behavior

People tend to rate prosocial or positive behavior as more strongly influenced by the actor's genes than antisocial or negative behavior. The current study tested whether people would show a similar asymmetry when rating the role of genes in their own behavior, and if so, what variables might mediate this difference. Participants were prompted to think about an example of their own behavior from the past year that was either prosocial or antisocial. Those in the prosocial condition rated the role of genetics in causing the behavior as significantly greater than did those in the antisocial condition. A mediation analysis suggested that this asymmetry could be accounted for by a tendency to view prosocial behavior as more natural and more aligned with one's true self than antisocial behavior. These findings add to a growing body of evidence suggesting that people's reasoning about genetics may be influenced by evaluative judgments.

Physician weight influences responses to a public health message about the genetics of obesity

OBJECTIVE

Many patients prefer lean physicians to physicians with obesity and place higher credence in their weight management advice. Because genetic information about weight can be viewed as self-serving for individuals with overweight or obesity, physicians with obesity may be discounted when sharing such information. As provision of genetic information regarding weight becomes increasingly common in public health messaging, could a physician's own weight influence how these messages are received by the public?

METHODS

In an online survey, 967 participants were randomly assigned a physician profile (lean v. has obesity) with a media interview transcript discussing genetic factors of a common health condition (obesity v. osteoporosis).

RESULTS

Participants perceived the physician with obesity who discussed genetic factors in obesity as less trustworthy and less credible. Participants were also less likely to anticipate following her advice on weight-related issues. Participants with higher BMI had less negative perceptions of this physician.

CONCLUSION

Physicians with obesity, when providing public health messaging regarding genetic information about obesity, may be met with distrust and negative attitudes toward the physician.

PRACTICAL IMPLICATIONS

Future research should investigate health communication strategies that address this form of weight stigma while accurately conveying genetic factors that contribute to weight.

Genetic determinism, essentialism and reductionism: semantic clarity for contested science

Research linking genetic differences with human social and behavioural phenotypes has long been controversial. Frequently, debates about the ethical, social and legal implications of this area of research centre on questions about whether studies overtly or covertly perpetuate genetic determinism, genetic essentialism and/or genetic reductionism. Given the prominent role of the '-isms' in scientific discourse and criticism, it is important for there to be consensus and clarity about the meaning of these terms. Here, the author integrates scholarship from psychology, genetics and philosophy of science to provide accessible definitions of genetic determinism, genetic reductionism and genetic essentialism. The author provides linguistic and visual examples of determinism, reductionism and essentialism in science and popular culture, discusses common misconceptions and concludes with recommendations for science communication.

Using Educational Videos and Perspective-Taking to Communicate Gene-By-Environment Interaction Concepts about Eating Behavior: Effects on Empathy and Weight Stigma

OBJECTIVE

This study investigated whether education about gene-by-environment interaction (G × E) concepts could improve G × E knowledge and positively affect empathy and weight stigma.

DESIGN

We conducted a randomized trial using a 2 × 2 between-subjects design.

SETTING

Online.

PARTICIPANTS

Five hundred eighty-two American participants from the Prolific platform.

INTERVENTION

Participants were randomly assigned to watch an educational or a control video. Participants then watched a set of vignette scenarios that depicted what it is like to have a predisposition toward obesogenic eating behaviors from either a first-person or third-person perspective.

MAIN OUTCOME MEASURE(S)

Participants completed questionnaires measuring G × E knowledge, causal attributions, weight stigma, and empathy postintervention.

ANALYSIS

Two-by-two between-subjects ANOVAs and exploratory mediation analyses were conducted.

RESULTS

Participants who watched the educational video demonstrated greater G × E knowledge, reported higher empathy toward the characters in the vignette scenarios and held fewer stigmatizing attitudes (notably blame) toward individuals with higher weight. Exploratory mediation analyses indicated that the educational video led to these positive downstream effects by increasing the extent to which participants attributed genetic causes to eating behaviors.

CONCLUSIONS AND IMPLICATIONS

Education about G × E causes of eating behaviors can have beneficial downstream effects on attitudes toward people with higher weight.

Genetic and Environmental Factors of Non-Ability-Based Confidence

Non-ability-based confidence is confidence in one's ability that is not calibrated to actual ability. Here, we examine what psychological factors are associated with possessing more or less confidence relative to one's ability and to what extent genetic and environmental processes contribute to these links. Using data from the Texas Twin Project (N = 1,588 participants, aged 7-15 years), we apply a latent variable residual approach to calculate non-ability-based confidence as self-rated confidence net of ability on standardized cognitive tests. Non-ability-based confidence was modestly heritable (9%-28%) and strongly positively correlated with the need for cognition, mastery goal orientation, grit, openness, and emotional stability. These correlations were partly mediated by genetic factors (57% of the association on average). This widespread pattern of associations between non-ability-based confidence and several other measures of thinking, feeling, and acting suggest that non-ability-based confidence can be conceptualized as a personality attribute.

Bench Research Informed by GWAS Results

Scientifically interesting as well as practically important phenotypes often belong to the realm of complex traits. To the extent that these traits are hereditary, they are usually 'highly polygenic'. The study of such traits presents a challenge for researchers, as the complex genetic architecture of such traits makes it nearly impossible to utilise many of the usual methods of reverse genetics, which often focus on specific genes. In recent years, thousands of genome-wide association studies (GWAS) were undertaken to explore the relationships between complex traits and a large number of genetic factors, most of which are characterised by tiny effects. In this review, we aim to familiarise 'wet biologists' with approaches for the interpretation of GWAS results, to clarify some issues that may seem counterintuitive and to assess the possibility of using GWAS results in experiments on various complex traits.

Can we get human nature right?

Few questions in science are as controversial as human nature. At stake is whether our basic concepts and emotions are all learned from experience, or whether some are innate. Here, I demonstrate that reasoning about innateness is biased by the basic workings of the human mind. Psychological science suggests that newborns possess core concepts of "object" and "number." Laypeople, however, believe that newborns are devoid of such notions but that they can recognize emotions. Moreover, people presume that concepts are learned, whereas emotions (along with sensations and actions) are innate. I trace these beliefs to two tacit psychological principles: intuitive dualism and essentialism. Essentialism guides tacit reasoning about biological inheritance and suggests that innate traits reside in the body; per intuitive dualism, however, the mind seems ethereal, distinct from the body. It thus follows that, in our intuitive psychology, concepts (which people falsely consider as disembodied) must be learned, whereas emotions, sensations, and emotions (which are considered embodied) are likely innate; these predictions are in line with the experimental results. These conclusions do not speak to the question of whether concepts and emotions are innate, but they suggest caution in its scientific evaluation.

Public knowledge and opinion of epigenetics and epigenetic concepts

The field of epigenetics is currently one of the most rapidly expanding in biology and has resulted in increasing public interest in its applications to human health. Epigenetics provides a promising avenue for both targeted individual intervention and public health messaging. However, to develop effective strategies for engagement, it is important to understand the public's understanding of the relevant concepts. While there has been some research exploring the public's understanding of genetic and environmental susceptibility to disease, limited research exists on public opinion and understanding of epigenetics and epigenetic concepts. Using an online questionnaire, this study investigated the Australian public's understanding, views, and opinions of epigenetics and related concepts, including the concepts of the developmental origins of health and disease (DOHaD) and the first 1000 days. Over 600 questionnaires were completed, with 391 included in the analysis. The survey included questions on knowledge of epigenetics and perceptions of epigenetic concepts for self and for children. Data were analyzed using predominately descriptive statistics, with free-text responses scored based on concordance with predetermined definitions. While participants' recognition of epigenetic terms and phrases was high, their understanding was limited. The DOHaD theory was more accurately understood than the first 1000 days or epigenetics itself. Female participants without children were more likely to recognize the term epigenetics, while age also had an impact. This research provides a solid foundation for further detailed investigation of these themes, all of which will be important data to help inform future public health messages regarding epigenetic concepts.

Investigating perceived heritability of mental health disorders and attitudes toward genetic testing in the United States, United Kingdom, and Australia

Our beliefs about the heritability of psychiatric traits may influence how we respond to the use of genetic information in this area. In the present study, we aim to inform future education campaigns as well as genetic counseling interventions by exploring common fears and misunderstandings associated with learning about genetic predispositions for mental health disorders. We surveyed 3,646 genetic research participants from Australia, and 960 members of the public from the United Kingdom, and the United States, and evaluated attitudes toward psychiatric genetic testing. Participants were asked hypothetical questions about their interest in psychiatric genetic testing, perceived usefulness of psychiatric genetic testing, and beliefs about malleability of behavior, among others. We also asked them to estimate the heritability of alcohol dependence, schizophrenia, and major depression. We found a high interest in psychiatric genetic testing. In most cases, more than a third of the participants showed serious concerns related to learning about personal genetic predisposition, such as not wanting to have children if they knew they had a high genetic predisposition, or not wanting to choose a partner with a high genetic predisposition for a mental health problem. Finally, we found a significant association between most participants' attitudes and their lay estimates of heritability, which highlights the complexity of educating the public about genetics.

What Do People Know About the Heritability of Sleep?

STUDY OBJECTIVES

Twin studies have provided data about the relative weight of genetic and environmental factors on sleep variables over the last few decades. However, heritability is a non-intuitive concept and it is often misunderstood even amongst the scientific community. This study aimed to analyze: (1) understanding of the meaning of heritability of insomnia; (2) the accuracy of estimations of heritability in the general population regarding three sleep traits (sleep duration, sleep quality and insomnia); (3) perceptions of the effectiveness of different treatments for insomnia depending on how the disorder is presented (i.e. having an environmental or genetic etiology) and whether the subject's estimate of genetic influence on sleep traits impacted beliefs about the effectiveness of different treatments.

METHODS

Participants (N = 3658) completed a survey which included: questions about general genetic knowledge; a specific question about the meaning of heritability; estimates of heritability of three different sleep traits; and the effectiveness of different treatments for insomnia depending on how the etiology of this condition was presented.

RESULTS

Fewer than 25% of the participants selected the correct description of the heritability of insomnia. Almost half of the sample incorrectly believed that heritability refers to the chance of passing a disorder onto their children. We also found that participants provided different estimates for the effectiveness of different treatments depending on the presumed etiology of the disorder.

CONCLUSION

Most people do not have accurate knowledge about the concept of heritability. People's assumptions about the etiology of a disorder may influence which treatments they consider most effective.

"Reports of My Death Were Greatly Exaggerated": Behavior Genetics in the Postgenomic Era

Behavior genetics studies how genetic differences among people contribute to differences in their psychology and behavior. Here, I describe how the conclusions and methods of behavior genetics have evolved in the postgenomic era in which the human genome can be directly measured. First, I revisit the first law of behavioral genetics stating that everything is heritable, and I describe results from large-scale meta-analyses of twin data and new methods for estimating heritability using measured DNA. Second, I describe new methods in statistical genetics, including genome-wide association studies and polygenic score analyses. Third, I describe the next generation of work on gene × environment interaction, with a particular focus on how genetic influences vary across sociopolitical contexts and exogenous environments. Genomic technology has ushered in a golden age of new tools to address enduring questions about how genes and environments combine to create unique human lives.

It’s in Your Control: Free Will Beliefs and Attribution of Blame to Obese People and People with Mental Illness

People’s belief in free will is shown to influence the perception of personal control in self and others. The current study tested the hypothesis that individuals who believe in free will attribute stronger personal blame to obese people and to people with mental illness (schizophrenia) for their adverse health outcomes. Results from a sample of 1110 participants showed that the belief in free will subscale is positively correlated with perceptions of the controllability of these adverse health conditions. The findings suggest that free will beliefs are correlated with attribution of blame to people with obesity and mental health issues. The study contributes to the understanding of the possible negative implications of people’s free will beliefs.

Minnesota Center for Twin and Family Research

The Minnesota Center for Twin and Family Research (MCTFR) comprises multiple longitudinal, community-representative investigations of twin and adoptive families that focus on psychological adjustment, personality, cognitive ability and brain function, with a special emphasis on substance use and related psychopathology. The MCTFR includes the Minnesota Twin Registry (MTR), a cohort of twins who have completed assessments in middle and older adulthood; the Minnesota Twin Family Study (MTFS) of twins assessed from childhood and adolescence into middle adulthood; the Enrichment Study (ES) of twins oversampled for high risk for substance-use disorders assessed from childhood into young adulthood; the Adolescent Brain (AdBrain) study, a neuroimaging study of adolescent twins; and the Siblings Interaction and Behavior Study (SIBS), a study of adoptive and nonadoptive families assessed from adolescence into young adulthood. Here we provide a brief overview of key features of these established studies and describe new MCTFR investigations that follow up and expand upon existing studies or recruit and assess new samples, including the MTR Study of Relationships, Personality, and Health (MTR-RPH); the Colorado-Minnesota (COMN) Marijuana Study; the Adolescent Brain Cognitive Development (ABCD) study; the Colorado Online Twins (CoTwins) study and the Children of Twins (CoT) study.

Potential use of clinical polygenic risk scores in psychiatry - ethical implications and communicating high polygenic risk

Psychiatric disorders present distinct clinical challenges which are partly attributable to their multifactorial aetiology and the absence of laboratory tests that can be used to confirm diagnosis or predict risk. Psychiatric disorders are highly heritable, but also polygenic, with genetic risk conferred by interactions between thousands of variants of small effect that can be summarized in a polygenic risk score. We discuss four areas in which the use of polygenic risk scores in psychiatric research and clinical contexts could have ethical implications. First, there is concern that clinical use of polygenic risk scores may exacerbate existing health inequities. Second, research findings regarding polygenic risk could be misinterpreted in stigmatising or discriminatory ways. Third, there are concerns associated with testing minors as well as eugenics concerns elicited by prenatal polygenic risk testing. Fourth, potential challenges that could arise with the feedback and interpretation of high polygenic risk for a psychiatric disorder would require consideration. While there would be extensive overlap with the challenges of feeding back genetic findings in general, the potential clinical use of polygenic risk scoring warrants discussion in its own right, given the recency of this possibility. To this end, we discuss how lay interpretations of risk and genetic information could intersect. Consideration of these factors would be necessary for ensuring effective and constructive communication and interpretation of polygenic risk information which, in turn, could have implications for the uptake of any therapeutic recommendations. Recent advances in polygenic risk scoring have major implications for its clinical potential, however, care should be taken to ensure that communication of polygenic risk does not feed into problematic assumptions regarding mental disorders or support reductive interpretations.