Why Are Extraverts More Popular? Oral Fluency Mediates the Effect of Extraversion on Popularity in Middle Childhood VILLE-JUHANI ILMARINEN 1 , MARI-PAULIINA VAINIKAINEN 2 , MARKKU VERKASALO 1 and JAN-ERIK LÖNNQVIST 3 * 1 Institute of Behavioural Science, University of Helsinki, Finland 2 Centre for Educational Assessment, University of Helsinki, Finland 3 Swedish School of Social Science, University of Helsinki, Finland Abstract: In a sample of 7- to 8-year-old children (N = 760), we examined the associations between personality traits, oral fluency and sociometric popularity. Extending upon research conducted with older populations, we found parent ratings of extraversion at age 7 to predict popularity one year later. More importantly, we expected and found teacher-rated oral fluency to partially mediate the positive association between extraversion and popularity. This me- diation effect was independent of psychometrically assessed working memory, academic skills and gender. Our results can be interpreted as suggesting that a Matthew effect, similar to the one proposed for early reading skills and cognitive ability, may be operating in the domain of social competence. Copyright © 2015 European Association of Personality Psychology Key words: development of personality; social and personal relationships; social competence; social interaction INTRODUCTION Why are some children popular and others unpopular? In re- cent years, the evidence has accumulated that a certain per- sonality disposition, that is, extraversion, is associated with being popular. However, the explanation that certain kids are popular because they are extraverted begs the questions of why those who are extraverted are more popular. The fo- cus of the present research is on the mechanisms through which children’s personality may influence their popularity. In adulthood, behavioural manifestations of extraversion, such as strength of voice, have been associated with positive first impressions (Back, Schmukle, & Egloff, 2011), which could in part help explain the association between extraver- sion and popularity. However, other mechanisms may be at play in childhood, especially in contexts such as in the class- room, in which first impressions are likely to be less impor- tant than in many other contexts—whereas first impressions may in some context determine whom people approach, sit next to or engage in conversation with, thereby determining opportunities to learn to know people, children attending the same class will over time learn to know all of their class- mates. We will investigate, in a sample of 7- to 8-year-olds, the following: (i) whether extraversion, already at the begin- ning of middle childhood, is associated with popularity; and (ii) whether the predicted association between extraversion and popularity can be explained by the greater oral fluency of extraverts. Popularity In general terms, popularity is characteristic of an individual that reflects whether the individual is generally liked, ac- cepted and preferred as an interaction partner. It is a form of social status that is unilateral (as opposed to reciprocated social relation between two individuals); it reflects how others perceive the individual and how much they like the in- dividual (Bukowski, Pizzamiglio, Newcomb, & Hoza, 1996). Although popularity is derived from the group, it is inevita- bly influenced by the behaviours and characteristics of the individual. Popularity as a concept reflective of peer status is com- monly studied in one of two somewhat distinct forms. The focus of the present study is on ‘sociometric popularity’ (later also referred to as ‘popularity’), which is distinguished from ‘perceived popularity’ (Parkhurst & Hopmeyer, 1998). Sociometric popularity is measured by items such as ‘this person is likeable’ or ‘I like to play/work with this person’, and perceived popularity by items such as ‘how popular is this person?’ (Cillessen & Mayeux, 2004). Sociometric popularity is weighted towards likeability and preference, whereas perceived popularity is more a reflection of visibility and social centrality (Parkhurst & Hopmeyer, 1998). Al- though the different types of popularity are interrelated, they also have distinct predictors, correlates and outcomes (Cillessen & Rose, 2005; Mayeux, Houser, & Dyches, 2011; Rodkin, Ryan, Jamison, & Wilson, 2012). It should be noted, however, that the younger the studied age group, the more the two forms of popularity overlap (Cillessen & Mayeux, 2004; Rodkin et al., 2012). Whereas 10- and 13-year-old children’s descriptions of ‘popular children’ (per- ceived popularity) included mentions of physical appearance, *Correspondence to: Jan-Erik Lönnqvist, Swedish School of Social Science, University of Helsinki, Finland. E-mail: jan-erik.lonnqvist@helsinki.fi European Journal of Personality, Eur. J. Pers. 29: 138–151 (2015) Published online in Wiley Online Library (wileyonlinelibrary.com) DOI: 10.1002/per.1982 Received 17 June 2014 Revised 15 December 2014, Accepted 17 December 2014 Copyright © 2015 European Association of Personality Psychology