These findings refine the conceptualisation of social-cognitive processes across autistic traits while highlighting the importance of large samples for validating null effects.
However, we found strong evidence for the absence of relationships between autistic trait scores and both self-bias (BF01 = 32.13) and social basis function use (BF01 = 7.04), indicating preserved self–other integration during social decision-making.
We also observed the expected relationships between autistic traits and mental health questionnaire measures. For example, autistic trait scores were negatively correlated with cognitive empathy, but not affective empathy. These findings support the validity of the questionnaire measures.
We replicated the self-bias and effects of social basis function use across four experiments. These effects also tracked meaningful social-cognitive computations, with social basis function use increasing as the percentage of group decisions increases.
We used the well-established social group paradigm (www.nature.com/articles/s41...), developed by @mkwittmann.bsky.social, to distil precisely controlled measures of self-bias and social basis function use as two indices of self-other integration.