Many cognitive neuroscientists believe that both a large brain and an isocortex are crucial for complex cognition. Yet corvids and parrots possess non-cortical brains of just 1–25 g, and these birds exhibit cognitive abilities comparable with chimpanzees, which have brains of about 400 g. This paper offers an explanation for this riddle and proposes four features that may be required for complex cognition. These four neural features have convergently evolved in birds and mammals and may therefore represent ‘hard to replace’ mechanisms enabling complex cognition.

Güntürkün, O., Pusch, R., Rose, J., Why birds are smart, Trends Cogn. Sci., 2024, 28: 197-209.