What biological indicator strongly suggests the Shortfin Mako shark's intelligence?

The largest brain-to-body size ratio found among all shark species

The most compelling anatomical evidence presented for the Shortfin Mako shark's enhanced cognitive capacity is its neuroanatomy, specifically its brain-to-body size ratio. In comparative biology, this ratio serves as a proxy measurement for potential cognitive complexity. A larger brain relative to the physical mass it must govern suggests that a greater portion of the animal's processing power is allocated toward sophisticated functions such as sensory integration, the ability to solve novel problems encountered in the environment, and the execution of complex behaviors. While a true, standardized IQ score cannot be assigned to the Mako, this superior anatomical characteristic positions it uniquely when evaluating potential intelligence within the classification of sharks.