A video-based performance measure of mentalizing: participants watch a short film of four people at a dinner party and answer multiple-choice questions about the characters’ mental states. This is a COSMIN construct-validity synthesis - how well MASC scores behave as a measure of social cognition - not a treatment review and not a test of diagnostic accuracy.

Total score

Cognitive ToM

Affective ToM

Overmentalizing errors

Undermentalizing errors

No-mentalizing errors

Total errors

Movie for the Assessment of Social Cognition

Healthy controls

Autism (ASD)

Schizophrenia (SSD)

Depression (MDD)

Convergent validity

Discriminant validity

Concurrent clinical validity

Ecological validity

Known-groups validity

MASC indexTotal score (primary)	Healthy controls	Autism (ASD)	Schizophrenia (SSD)	Depression (MDD)	Overallall populations
Convergent validityDoes the MASC agree with other mentalizing tests?	Validity:SmallCertainty:Very LowStudies:23	Validity:UnclearCertainty:Very LowStudies:5	Validity:UnclearCertainty:Very LowStudies:3	Validity:UnclearCertainty:Very LowStudies:2	Validity:SmallCertainty:Very LowStudies:24
Discriminant validityIs the MASC distinct from IQ / neurocognition?	Validity:SmallCertainty:Very LowStudies:25	Validity:UnclearCertainty:Very LowStudies:5	Validity:ConcernCertainty:Very LowStudies:8	Validity:UnclearCertainty:Very LowStudies:2	Validity:SmallCertainty:Very LowStudies:28
Concurrent clinical validityDoes the MASC track psychopathology severity?	Validity:SmallCertainty:Very LowStudies:18	Validity:UnclearCertainty:Very LowStudies:4	Validity:SmallCertainty:Very LowStudies:8	Validity:UnclearCertainty:Very LowStudies:4	Validity:SmallCertainty:Very LowStudies:26
Ecological validityDoes the MASC relate to real-world social functioning?	Validity:UnclearCertainty:Very LowStudies:4	–	Validity:UnclearCertainty:Very LowStudies:2	–	Validity:SmallCertainty:Very LowStudies:6
Known-groups validityDo clinical groups score below controls, as expected?	–	Validity:GoodCertainty:Very LowStudies:5	Validity:UnclearCertainty:Very LowStudies:5	Validity:UnclearCertainty:Very LowStudies:4	Validity:GoodCertainty:Very LowStudies:13
Incremental validityEvidence gapDoes the MASC add anything beyond the tests already in use?	0 studies - This has not yet been tested in a study across all our populations. Whether the MASC is useful in practice depends on whether it provides clinicians with new information that goes beyond what IQ and existing social cognition tests offer. One research priority will be to explore this question.

MASC construct validity