Relative Contributions of BAP Subdomains to Social Relationships and Loneliness

Background: The broader autism phenotype (BAP) is a milder expression of social, nonsocial and language impairments seen in autism spectrum disorder (ASD). Previous research shows that individuals with high BAP scores have greater social cognitive difficulties, including emotion recognition, face processing, and gaze reciprocity, similar to the social difficulties that affect those with ASD.  Individuals with BAP exhibit poorer quality of interpersonal relationships and are also generally lonelier. But, how different aspects of the broad autism phenotype contribute to specific aspects of their social relationships remains less unclear.

Objectives: This study aims to elucidate the relationships between BAP characteristics and its subdomains (i.e. social aloofness, pragmatic language difficulties, and rigidity) and various aspects of social relationships and self-reported loneliness in a large sample of non-ASD individuals.

Methods: One thousand six hundred fifty nine neurotypical undergraduate students (1113 female) participated in this study. All participants completed the Broader Autism Phenotype Questionnaire (BAPQ) (Hurley et al., 2007), the Friendship Questionnaire (FQ), which measures the extent to which people enjoy close friendships (Baron-Cohen & Wheelwright, 2003), the UCLA Loneliness Scale (Russell, 1996), and a romantic relationship questionnaire consisting of questions about current relationship status and future marital aspirations.

Results: Total BAP scores were negatively correlated with quality of friendships (FQ; r=-0.37; p<0.001) and positively correlated with loneliness (r=0.59; p<0.001) – i.e., individuals with more BAP characteristics had lower quality friendships and were lonelier. Multiple regression analyses revealed that the different BAP subscales (i.e. aloof, pragmatic language and rigidity) contributed in different ways to both friendship quality and loneliness. High levels of aloofness (β=-0.48, p<0.001) negatively predicted the quality of friendships, while high levels of rigidity was related positively, though weakly (β=0.07, p=0.004). Pragmatic language impairment was unrelated to the quality of friendships (β=0.02, p=0.51). However, pragmatic language impairment was a positive predictor of loneliness (β=0.21, p<0.001) as was aloofness (β=0.47, p<0.001), while rigidity was unrelated (β=0.02, p=0.30). In terms of romantic relationships, participants who were single compared to those in committed relationships reported greater pragmatic language difficulties (t[1434]=2.21, p=0.027) and higher levels of loneliness (t[1490]=2.81, p=0.005). Finally, those participants who reported not having any future thoughts about marriage had higher levels of aloofness (t[1596]=6.77, p<0.001) and exhibited greater pragmatic language difficulties (t[1577]=4.22, p<0.001). 

Conclusions: These findings replicate and extend previous research (Jobe & White, 2007; Wainer et al., 2013) suggesting individuals with greater BAP traits show difficulties in interpersonal relationships and higher levels of self-reported loneliness. Additionally, we find that various components of BAP that may be uniquely associated with different aspects of interpersonal relationships. For example, pragmatic language difficulties predicted relationship status and loneliness, but not the quality of friendships, highlighting the role of pragmatic language in initiating these relationships. In contrast, aloofness seemed to have a different role, affecting friendship quality, and loneliness but not one’s relationship status. Overall, these results suggest that there may be specific targets of intervention within the triad of difficulties that can help promote the successful formation and maintenance of social relationships in individuals with ASD.