The double-edged sword of autistic traits: opposing pathways to loneliness via friendship similarity in Chinese adults

BackgroundLoneliness is a pervasive concern in the Broader Autism Phenotype, yet research often treats autistic traits as homogeneous risk factor, obscuring potential adaptive pathways. The distinct roles of social-communicative difficulties versus cognitive traits (e.g., Attention to Detail) in shaping friendship remain underexplored, particularly in non-Western contexts.MethodA sample of 1,076 Chinese adults completed the Autism Spectrum Quotient, adapted friendship similarity items (interest and personality similarity), the UCLA Loneliness Scale, and the Satisfaction with Life Scale. After excluding 4 participants with non-binary gender, the analytical sample was 1,072. Serial mediation models with 5,000 bootstrap resamples were employed to examine whether autistic trait dimensions indirectly predicted life satisfaction through interest similarity and loneliness.ResultsAnalyses revealed divergent pathways. Social skills (β = −0.105) and communication (β = −0.117) difficulties negatively predicted interest similarity, whereas Attention to Detail was a positive predictor (β = 0.059). Serial mediation confirmed that Attention to Detail had a significant positive indirect effect on life satisfaction via the interest similarity, loneliness chain [indirect effect = 0.00059, bias-corrected 95% CI (0.00006, 0.00159)], contrasting with the negative indirect effects of Social Skills (indirect effect = −0.00083) and Communication (indirect effect = −0.00123). A robustness check using personality similarity as mediator showed that the protective effect was specific to interest similarity.ConclusionThese findings challenge the monolithic deficit model by identifying Attention to Detail as a protective factor facilitating interest-based friendship connection. Distinguishing between social and cognitive autistic trait dimensions is crucial for developing tailoring, interest-based interventions to alleviate loneliness in Chinese adults.