Humans are inherently social and desire belongingness to social groups (Baumeister & Leary, 1995; Tajfel & Turner, 1986). According to social identity theory, identifying with a group provides psychological benefits (Tajfel & Turner, 1986). Group identification constitutes the basis on which individuals build their sense of self (Turner, Hogg, Oakes, Reicher, & Wetherell, 1987), and entails psychological investment in the group (Tajfel & Turner, 1979; Tajfel & Turner, 1986). Ingroup identification necessitates the existence of one or more outgroups (Brewer, 1991; Gustafsson Sendén et al., 2014b). Hence, as an individual starts to identify with a group they should also show signs of differentiation to other group(s).

When an individual starts identifying with a group, the group also exerts influence on the individual members (Kelman, 1958). Social influence is broadly defined as any change - emotional, behavioral, or attitudinal – that has its roots in others’ real or imagined presence (Allport, 1954). There are many different forms of social influence defined in the literature, such as conformity, compliance, obedience, internalization and identification to mention a few. What differs between these forms is the reason for the observable adaption. The reason may be a genuine attitude shift, such as when an individual internalizes attitudes, which could be based on identification with a group (Deutsch & Gerard, 1955; Miller & Prentice, 1996). It could also be public compliance displayed for increased acceptance that is not accompanied with a genuine attitude change (Goldstein, Cialdini, & Griskevicius, 2008). Regardless of why an individual displays an observable behavioral change that is in line with group norms, social identification with a group is the basis for the change.

In social psychological terms, a group is defined as more than two people that share certain goals (Cartwright & Zander, 1968). However, research also shows that even the most arbitrary shared attribute has the power to elicit group processes (Tajfel & Turner, 1986), known as ‘minimal groups’ (Tajfel, 1970). An example of this is that splitting people arbitrarily into a red and blue group leads to intergroup differentiation (Frank & Gilovich, 1988). In line with this, much research has established that attitudes have the power to function as group boundaries (Bäck et al., 2011; Biernat & Vescio, 1993; Kenworthy & Miller, 2002; Mackie, Devos, & Smith, 2000; Simon, Hastedt, & Aufderheide, 1997). Hence, it is possible to think of online communities, where the members may share certain attitudes, as psychological groups that provide individuals with the benefits of being part of a group similarly as any real life group would. Moreover, such groups should exert the same sort of social influence as other groups (Tajfel & Turner, 1986). Processes of social identification, intergroup differentiation and social influence have to date not been studied in online forums. The aim of the present research is to fill this gap and provide information on how such processes can be studied through language used on the forum.

In order to explore processes of social identification, intergroup differentiation and social influence in an existing online setting, one is limited to the written text provided by the users. Of crucial importance is how such processes can be captured and analyzed using only written language available from the posts on the forum. Previous research indicates that language has the potential to provide such information, for instance through the analysis of the use of personal pronouns, and other word choices.

It is commonly assumed that the Internet has significantly changed the forms of political engagement, especially for radical political groups ( Thompson, 2011 ). The Internet has provided radical groups with important platforms for exchange of ideas, ideological development, and resources for marketing ( Edwards & Gribbon, 2013 ; Neumann, 2013 ). In addition, as many of these forums are open for public view they provide an important source of insight into how radical politics is justified, motivated, and narrated (see Owens & Palmer, 2003 ; Caiani & Parenti, 2009 ). This is knowledge that has previously been hard to attain due to the lack of access to radical groups and their arguments.

The political arena today is becoming increasingly polarized and right-wing populism is increasing across the globe. One of the most important political issues is immigration, where populist parties create anti-immigration sentiments increasing intergroup differentiation ( Bäck & Bäck, 2017 ; Mudde, 2007 ; Stanley, 2008 ). Studying how anti-immigrant ideas are discussed and evolved among the population have been difficult for several reasons. First, individuals sympathizing with right-wing populist parties are difficult for researchers to reach. Second, because anti-immigrant attitudes have been strongly disapproved of, the arenas where such sentiments can be voiced have been closed to outsiders.

The popularity of social networking sites has increased immensely during the last decade. At the same time, offline socializing has shown a decline ( Duggan & Smith, 2013 ). Now, much of the socializing actually takes place online ( Ganda, 2014 ). In order to be part of an online community, the individual must socialize with other users. Through such socializing, individuals create self-representations ( Enli & Thumim, 2012 ). Hence, the processes of identity formation, may to a large extent take place on the Internet in various online forums.

Personal Pronouns as Markers of Identity and Group Differentiation TOP]

Personal pronouns are linguistic elements that indicate how individuals view their roles in social groups (Campbell & Pennebaker, 2003; Chung & Pennebaker, 2007; Pennebaker, 2011a). Personal pronouns substitute and represent social categories, but do not explicitly refer to particular groups. As such, they are used relative to the speaker’s point of view and provide a non-reactive way to explore social psychological phenomena. Past research has shown that pronoun use is correlated with status, group identity and social relations (Chung & Pennebaker, 2007; Gustafsson Sendén, Lindholm, & Sikström, 2014a, 2014b; Kacewicz et al., 2013). For example, a shift from ‘I’ to ‘We’ was found to reflect a change from an individual to a collective identity (Brewer & Gardner, 1996; Fitzsimons & Kay, 2004; Gustafsson Sendén et al., 2014b). Social status is also related to the extent to which first person pronouns are used in communication. Low-status individuals use ‘I’ more than high-status individuals (Dino, Reysen, & Branscombe, 2009; Kacewicz et al., 2013; Pennebaker, 2011a; Slatcher, Chung, Pennebaker, & Stone, 2007), while high-status individuals use ‘we’ more often (Kacewicz et al., 2013; Slatcher et al., 2007). This pattern is observed both in real life and on Internet forums (Dino et al., 2009). Hence, a shift from “I” to “we” may signal an individual’s identification with the group and a rise in status when becoming an accepted member of the group.

Ingroup identification also implies differentiation to one or more outgroups (Brewer, 1991). Ingroup identification and formation is also affected when there is perceived competition between groups (Brewer, 1991). In the classical experiments by Sherif and colleagues (Sherif et al., 1961), the ingroup became more cohesive when competition with other groups was salient. In addition, social exclusion functions to strengthen the ingroup (Williams, 2007). In a political setting, populist and anti-immigrant arguments build on the differentiation between an ingroup and one or more outgroups. For instance, linguistic analyses of American Nazis have shown that use of third person plural pronouns (they, them, their) is the single best predictor of extreme attitudes (Pennebaker & Chung, 2008).

Taken together, previous research shows that it is possible to study group formation and differentiation through linguistic signals. Especially, this should be shown in a shift from ‘I’ to ‘We’ (Brewer & Gardner, 1996; Fitzsimons & Kay, 2004; Gustafsson Sendén et al., 2014b; Pennebaker, 2011a), but also in an increased differentiation to one or more outgroups as signaled by increased use of ‘they’ (Pennebaker & Chung, 2008). Drawing on this literature, we present a first hypothesis saying that the use of ‘I’ will decrease over time and the use of ‘we’ and ‘they’ will increase relative to the overall usage of pronouns (H1).

Being part of a social group also entails that the individual member will change their behavior and attitudes to fit with the group (Tajfel & Turner, 1986). Regardless of why an individual displays changes in behavior or attitudes due to social influence from being a member of a group, such changes are markers of group influence. Norms can be created and sustained through group interactions and provide new members with guidelines to which they can adjust in order to be a valued member of the group. Because language can be seen as behavior (Fiedler, 2008), it may be possible to study processes of social influence through linguistic analysis. Thus, our second hypothesis is that the linguistic style of new users will become increasingly similar to the linguistic style of the overall forum over time (H2).

Finally, it is possible to detect changes in content of posts over time. There is an ongoing debate about how online communities function in their way of censoring or promoting development of ideas. Sunstein (2001) argues that online communities are so called ‘echo chambers’, where the same arguments are reinforced and repeated, and that such communities are closed for deviating ideas, which are censored (Jamieson & Capella, 2009). If an online forum functions as an echo chamber, we would not suspect much variation in the content of the posts over time, besides for perhaps the linguistic style. Because of their nature, echo chambers are detrimental to evolution of ideas, gaining knowledge and new perspectives.

However, this view of the Internet as being composed of echo chambers has been criticized (Brundidge, 2010). For example, Garrett (2009) argues that the Internet does not have the perfect conditions for avoiding unwanted information. On the contrary, it is difficult to completely avoid politically diverse information. Internet forums provide individuals with opportunities to discuss, develop ideas, and get new information from other members (Edwards & Gribbon, 2013; Neumann, 2013), and most likely they will meet contradicting arguments to which they need to respond. In fact, Karlsen et al. (2017) find that most people who participate in online discussions with like-minded others, also discuss with people who disagree with them, and very few people state that they are never contradicted in online discussions. Moreover, most people state that encountering contradicting arguments leads to increased strength in their prior position, and almost half of the participants stated that they learned something from such contradicting arguments (Karlsen et al., 2017).

Taber and Lodge (2006) show that when individuals encounter evidence that supports or contradicts their prior political beliefs, they uncritically accept supporting arguments, but also actively counter contradicting arguments. Karlsen et al. (2017) show that this also happens in online political environments and that this results in strengthened attitude positions. The fact that one needs to counter contradicting arguments, may force individuals to more elaborate thinking. This indicates that the content of the posts in an online forum may also change over time as arguments become more fine-tuned and input from both supporting and contradicting members are integrated into an individual’s own beliefs. This is likely to result (linguistically) in an increase in indicators of cognitive complexity. Hence, we hypothesize that the content of the posts will change over time, such that indicators of complex thinking will increase (H3a).

Finally, it is possible that there will be a decrease in negative emotional content. This idea is primarily based on the nature of the specific forum under scrutiny. This forum is dominated by anti-immigrant sentiments, which may allure to individuals seeking an outlet for negativity surrounding immigration where this is perceived to be acceptable. Garcia and colleagues (2016) show that the content of individuals’ expression depends on their valence, and they show that their arousal significantly decreases afterwards as a regulation mechanism. This result indicates that after having expressed negativity in the forum, the need for such expressions should decrease. Hence, we expect that the content of the posts will change such that indicators of negative emotions will decrease, over time (H3b).

Through analyses of word use in posts and how they change over time, it is possible to capture both complex thinking and emotions. Words that reflect cognitive complexity include both content and function words. Content words for example include understand, realize and because. Function words for example include but, without, never, to and for. For instance, it has been shown that prepositions (e.g., to, for) signal that the speaker is providing more complex information about a topic (Fernández et al., 2013; Tausczik & Pennebaker, 2010). Higher use of these types of words has been related to the ability to juggle complex ideas (see Tausczik & Pennebaker, 2010, for a review).