Interpersonal similarity of autistic traits predicts friendship quality

Abstract

Autistic traits are known to be associated with social interaction difficulties. Yet, somewhat paradoxically, relevant research has been typically restricted to studying individuals. In line with the 'dialectical misattunement hypothesis' and clinical insights of intact social interactions among autistic individuals, we hypothesized that friendship quality varies as a function of interpersonal similarity and more concretely the difference value of autistic traits in a dyad, above and beyond autistic traits per se. Therefore, in this study, we used self-report questionnaires to investigate these measures in a sample of 67 neurotypical dyads across a broad range of autistic traits. Our results demonstrate that the more similar two persons are in autistic traits, the higher is the perceived quality of their friendship, irrespective of friendship duration, age, sex and, importantly, the (average of) autistic traits in a given dyad. More specifically, higher interpersonal similarity of autistic traits was associated with higher measures of closeness, acceptance and help. These results, therefore, lend support to the idea of an interactive turn in the study of social abilities across the autism spectrum and pave the way for future studies on the multiscale dynamics of social interactions.

Keywords: autism; dialectical misattunement hypothesis; double empathy problem; friendship; interpersonal similarity; second person neuropsychiatry.

Fig. 1.

Primary variables of the study: friendship quality, friendship duration, individual autistic traits and the mismatch of autistic traits (interpersonal difference of individual traits). Dots denote actual raw data, boxplots display sample median alongside interquartile range, while distribution ‘clouds’ portray a smoothed version of the histogram (cf. rain cloud plots; Allen et al., 2018).

Fig. 2.

Friendship (in rank values; vertical axes) and autistic traits (in rank values; horizontal axes): Interrelations of individual autistic traits (left column) and dyadic mismatch thereof (right column) with friendship quality (top row) and friendship duration (bottom row). Dyadic mismatch of autistic traits negatively correlated with both friendship quality and duration, while individual autistic traits did not significantly correlate with either of the friendship measures. Individual friendship quality refers to each individual’s impressions, while dyadic friendship quality to the average impressions within a given dyad. Please note there is only one value for each dyad in the pairwise mismatch measures, while individual traits are plotted for each participant. Regression lines and the 95% confidence bands were drawn with the bounded line toolbox (Kearney, 2020).

Fig. 3.

Bootstrap resampled correlation strengths: dyadic mismatch of autistic traits (orange) and individual autistic traits (; blue) correlations with friendship quality (top left) and friendship duration (top right). Distributions of correlation difference (; green) for friendship quality (bottom left) and friendship duration (bottom right). Dotted lines indicate zero level for correlation strength. The autistic trait mismatch correlation distributions (orange, top figures) lie almost completely on the negative side for both the cases of friendship quality and friendship duration. In the majority of resampled datasets, autistic trait mismatch appears stronger correlated with both friendship measures than the autistic traits do (part of the distributions below zero; green; bottom figures). Boxplots display sample median alongside interquartile range, while distribution ‘clouds’ portray a smoothed version of the histogram (cf. rain cloud plots; Allen et al., 2018).