Disentangling Language and Education Effects on False Belief Understanding: Evidence From Homesigners, Signers, and Unschooled Spanish Speakers

To investigate the contributions of language and education to Theory of Mind understanding, three Nicaraguan groups were tested using a minimally verbal protocol in which they themselves experienced a false belief instead of being told of one. We also assessed the relationship of executive function abilities to false belief performance. Homesigners, who have no linguistic community, did not succeed on either the False Belief or executive function tasks. Nicaraguan Sign Language users, who have educational experience and are part of an emerging linguistic community, performed the best on executive function, though less well on false belief, than Spanish speakers who have little to no education. This study showed that: without a language community, succeeding on either task is difficult; executive function may not be as tied to false belief performance as previously believed; and education may play a greater role in executive function success than language does.