Latent genetic traits account for, on average, 40.63% of variance in traditional and online political talk, discussion with agreement and disagreement, and political conflict avoidance: Results from two twin studies

Genetic influence on political discussion: Results from two twin studies. Chance York. Communication Monographs, Mar 26 2019. https://doi.org/10.1080/03637751.2019.1597274

ABSTRACT: Two twin studies are used to explore genetic influence on political discussion. Results from both studies demonstrate latent genetic traits account for, on average, 40.63% of variance in traditional and online political talk, discussion with agreement and disagreement, and political conflict avoidance. Taken together, the findings suggest a heritable genetic mechanism may partly explain why individuals vary across multiple dimensions of political discussion and differentially experience discussion effects. Implications for the political discussion effects literature and for reconceptualizing the etiology of political discussion are discussed.

KEYWORDS: Political discussion, individual differences, behavior genetics, twin study, genes

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Political discussion is an important and beneficial form of communication in representa-tive democracies. Citizens who frequently discuss politics become more knowledgeableabout current events and public affairs, engaged civically and politically, and confidentin their own ability to affect their national government and its institutions (Eveland &Hively,2009; Kenski & Stroud,2006; Shah et al.,2017). Yet, citizens differ widely in behav-ioral dimensions of political discussion and thus any potential benefits they may derivefrom talking about politics. For instance, some citizens routinely discuss politics whileothers only talk about politics during salient election periods (Hardy & Scheufele,2009)if they engage in political discussion at all. Some citizens prefer face-to-face talk whileothers prefer online conversation and some citizens seek political argument whileothers seek agreement.
What accounts for these individual differences in political discussion? In the past, indi-vidual differences in political discussion have been thought to emerge from, and be con-strained by, personality characteristics (Gerber, Huber, Doherty, & Dowling,2012;Hibbing, Ritchie, & Anderson,2011), parent and peer socialization (Hively & Eveland,2009; Klofstad,2009, 2010, 2015), and a wide array of psychological motivations as out-lined in the Uses and Gratifications (U&G) theory of communication behavior(Eveland, Morey, & Hutchens,2011; Gil de Zúñiga, Valenzuela, & Weeks,2016;Kearney,2017). However, it is also plausible that far more fundamental traits–genes–precede and delimit these more immediate influences on discussion. Because genes arecentral to neuroanatomical development and neurochemical responses to external stimuli (Hatemi, Byrne, & McDermott,2012; Knopik, Neiderhiser, DeFries, & Plomin,2016; Lockyer & Hatemi,2018), they may indirectly promote pathways to explicit behav-ioral patterns, including patterns of interpersonal political communication. In addition,genes have been shown to regulate personality characteristics amenable to political talk,such as extraversion (Bouchard & Loehlin,2001). This is perhaps why genetic traitshave already been shown to partially explain orientations to interpersonal discussion gen-erally (Kirzinger, Weber, & Johnson,2012) and frequency of political discussion specifi-cally (Funk et al.,2010), though it remains unclear whether genetic traits also influenceother critical dimensions of political talk, including online political talk and discussionwith disagreement.
The purpose of this article is to therefore explore genetic influence on previously unex-amined aspects of political discussion. In this article, a behavior genetics perspective andtwin study survey data were used to ascertain the amount of variance in several dimen-sions of political discussion that can be attributed to latent genetic traits and the socialenvironment. Building on previous research (Funk et al.,2010; Kirzinger et al.,2012),the results show that variation in multiple dimensions of political discussion is partlyexplained by genetics. Importantly, the results suggest genes may be an overlookedfactor motivating behavioral differences in political discussion and its effects. Moreover,the results imply a need to reconceptualize the etiology of political discussion as beingshaped by both social-environmental and biological forces.

Literature review

Talking about politics is associated with a number of desirable effects. For example, pol-itical discussion is related to enhanced knowledge about political candidates and issues(Eveland,2004; Eveland & Hively,2009), more frequent engagement in civic and electoralprocesses (Bakker & De Vreese,2011; Klofstad,2009, 2010, 2015) heightened confidenceone can make a difference politically (Kenski & Stroud,2006), and increased tolerance forindividuals with differing political opinions (Mutz,2002a). Political talk also acts as a keymediator of news media influence, altering selection and processing of news content(Anspach,2017) and augmenting positive effects of news exposure on civic and politicalparticipation by enabling citizens to make sense of mediated information (Cho et al.,2009;Shah et al.,2007, 2017; Shah, Cho, Eveland, & Kwak,2005). Although“cross-cutting”dis-cussion with un-likeminded partisans has been linked to reduced levels of participationwithin politically diverse social networks (Mutz,2002b, 2006), a considerable body of evi-dence has shown political discussion to be cognitively and behaviorally advantageous.
Individuals vary, however, in how they discuss politics and how frequently, and thusany informational and participatory benefits they may reap from discussion. Forexample, while some citizens are consistent political discussants regardless of external cir-cumstances, others might be characterized as“seasonal discussants”who are“uniformedand unengaged and usually do not participate in political discussions”unless they are“triggered by highly salient campaign coverage” (Hardy & Scheufele,2009, pp. 95–97).Still other citizens may avoid political talk altogether despite exposure to externalevents, such as national elections, and despite possessing a general interest in politics.Some citizens may prefer interactions that take place online while others seek out face-to-face conversation. Some may enjoy political discussion with disagreement whileothers abandon conflict in pursuit offinding common ground on the issues.
As with other forms of communication, several factors can motivate individual differences in political discussion. To date, in fact, the literature provides at least three sourcesof variation. First, political talk may arise from and be bounded by deeply ingrained personality characteristics such as extraversion. Extraversion, which can be defined as an“energetic approach to the social and material world”(Gerber, Huber, Doherty, &Dowling,2011, p. 267), has been linked to more frequent political discussion with friends, family, and distant social ties (Hibbing et al.,2011) as well as more frequent dis-cussions that involve disagreement (Gerber et al.,2012). Personality traits such as agree-ableness, conscientiousness, openness to experience, and emotional stability have alsobeen associated with political discussion frequency and discussion with disagreement(Gerber et al.,2012; Hibbing et al.,2011). From this perspective,“psychological predis-positions captured by individual personality traits play an important role in shaping thekinds of conversations citizens engage in, the setting for those conversations, and theinfluence discussion may or may not have on the individual”(Hibbing et al.,2011,p. 602).
Second, individual differences in political discussion may result from socialization viapolitical interactions with parents and peers that take place during childhood, adolescence,and young adulthood. Youth who belong to“concept-oriented”families that encouragekids to share their ideas, for instance, tend to engage in more frequent, more informedand“elaborative”talk with their families (Hively & Eveland,2009) that may, in turn,shape how they discuss politics in the future. Similarly, discussing politics with collegeroommates has been linked to increased short-term civic and political participation (Klof-stad,2009) and long-term discussion habits (Klofstad,2010; 2015). An individual’s earlyexposure to political talk, especially discussions with parents and peers, may thus play amajor role in discussion patterns over the life course.A third source of variation in political discussion comes from the U&G theory of com-munication behavior. Specifically, U&G suggests that individuals are active communica-tors who engage in interpersonal discussion in a manner that is“goal-directed,purposive, and motivated”by deliberate choices to satisfy immediate psychologicalneeds to communicate affection, promote feelings of social inclusion, escape from one’sday-to-day routines, and relax with close social ties (Rubin,2009a, p. 167; see Barbato,Graham, & Perse,1997, 2003; Graham, Barbato, & Perse,1993; Rubin,2009b; Rubin,Perse, & Barbato,1988).
Politically oriented discussions may likewise satisfy needs to per-suade politically, express political opinions, enhance issue learning (Eveland et al.,2011;Gil de Zúñiga et al.,2016; Yoo, Kim, & Gil de Zúñiga,2017), as well as maintain one’spolitical identity and feel emotionally engaged via political interaction (Kearney,2017;Valenzuela & Bachmann,2015). Accordingly, the U&G theoretical framework suggeststhat individual differences in political discussion occur because people perceive discussionto satisfy differing informational and social needs.
As Sherry (2001) has noted, however, it is likely that individual differences in U&G needs and the communication behaviors they inspire originate in biological factors. Forinstance, while it has been suggested that U&G needs for communication are governed by psychological“ predispositions [and] the environment”(Rubin,2009a, p. 167), such“predispositions”like those rooted in personality traits are known to have an even more fundamental genetic basis (e.g., Bouchard & Loehlin,2001; Plomin, DeFries, Knopik,& Neiderhiser,2016). Additionally, it is established that because genes form the basis of human neuroanatomical development and control neurochemical responses to external stimuli, they ultimately provide pathways to explicit cognitive and behavioral patterns(Hatemi et al.,2012; Lockyer & Hatemi, 2018), including neural pathways that, alongwith social contexts, prompt and structure communication behavior (Beatty, McCroskey, & Pence,2009; Weber, Sherry, & Mathiak, 2009). It is therefore possible, as decades of twin research in the behavior genetics paradigm has shown, “that many physical, psychological,and behavioral traits, however indirectly, are the ultimate result of a combination ofgenetic inheritance and the environment” (Medland & Hatemi,2009, p. 192).

A behavior genetics approach to communication behavior
Behavior genetics researchers rely on known degrees of biological relatedness among survey respondents–typically, identical and fraternal twins–to estimate the impactof genes on observable outcomes. These outcomes have included highly specializedpsychological orientations and behaviors, such as political ideology, political party affilia-tion, and voter turnout (Hatemi et al.,2014; Hatemi & McDermott,2012; Hatemi,Medland, Morley, Heath, & Martin,2007); social and economic attitudes (Hatemi,Smith, Alford, Martin, & Hibbing,2015); educational attainment (Cesarini & Visscher,2017); conservativism, authoritarianism, and religiousness (Ludeke, Johnson, & Bouchard,2013); fear of social and political out-groups (Hatemi, McDermott, Eaves,Kendler, & Neale,2013), risk-taking behavior (Kreek, Nielsen, Butelman, & LaForge, 2005); and social cooperation and trust (Cesarini et al.,2008). Twin studies have also shown that genes play a powerful role in shaping dimensions of mental health (Strachan,Duncan, Horn, & Turkheimer,2017), personality (Bouchard & Loehlin, 2001; Plominet al.,2016), and a variety of physical attributes such as height, weight, heart function,and facial structure (Polderman et al.,2015).1
In communication research, twin studies have demonstrated that genes partially explain differences in broad traits and orientations such as communicator style (Horvath,1995) and communicative adaptability (Beatty, Marshall, & Rudd,2001).
Twin studies have also been used to explore genetic influences on media consumptionand interpersonal communication behaviors. For example, one twin study demonstratedthat individual variation in mobile phone use, frequency of talking on mobile phones, andfrequency of texting were all indirectly influenced by genetic traits (Miller, Zhu, Wright,Hansell, & Martin,2012). Similar studies have shown that latent genetic traits influence frequency of using social media sites like Facebook to communicate with friends and family (York,2017), problematic internet use or PIU (Deryakulu & Ursavaş, 2014), and television viewing (Plomin, Corley, DeFries, & Fulker,1990).2
Across twin studies of communication, genetic traits have been shown to account forlarge proportions of individual variance in outcomes. For example, Kirzinger et al.(2012) showed genetic traits explained between 9% and 29% of the variance in orientationsto interpersonal discussion measured using two Likert-type items that tapped engagement in discussion and self-reported enjoyment in talking with“a lot of different people atparties”(p. 164). Funk et al. (2010, pp. 31–32) showed that up to a third of variance intwo Likert-type items measuring frequency of political discussion and conflict avoidance was explained by genes. These latter twin studies, combined with research that has foundthat genes provide brain–behavior pathways (Hatemi et al.,2012; Lockyer & Hatemi,2018) that activate patterns of communication (Beatty et al.,2009; Weber et al.,2009),suggest that additional dimensions of political talk may be partly explained by genetic traits. Thus, one could expect genetic traits to explain a nontrivial amount of variance in multiple dimensions of political talk, including traditional political discussion, online political discussion, political discussion with agreement and disagreement, and political conflict avoidance.In addition to examining whether genetic traits explain differences in dimensions of political discussion, it is also instructive in twin research to address the relative explana-tory contribution of genetic traits and the social environment shared by both twins (e.g.,being raised by the same parents) to the behaviors under investigation. Based on previousresearch, especially that of Kirzinger et al. (2012) and Funk et al. (2010), it may be the casethat both genetic and environmental factors shared by twins in a pair account for individ-ual differences in dimensions of political discussion, though it is uncertain which of thesefactors would make a more substantial contribution. Therefore, a research question is alsoposed:What is the relative explanatory contribution of genetic and environmental factors tovariance in multiple dimensions of political talk, including traditional political discussion,online political discussion, political discussion with agreement and disagreement, and pol-itical conflict avoidance?