Fig. 4: Differences in comprehension between language phenotypes.

Individuals with the syntactic and modifier phenotypes can follow the instruction “give me the short blue pencil” by recalling a pencil, and modifying its attributes, such as color and length, using the prefrontal modification (PFM) mechanism. In contrast, individuals with the command phenotype can understand individual words, but do not acquire the PFM mechanism. As a result, they struggle to identify the correct pencil among short/long straws, pencils, and Legos of different colors. This difficulty in integrating multiple elements into a coherent whole is known as stimulus overselectivity, tunnel vision, or the lack of multi-cue responsivity77,78,79,80.