Overview

• Published on August 19 in PNAS, the work synthesizes brain-development datasets spanning humans, marmosets, chimpanzees, and rhesus macaques from conception to adolescence.
• The comparative analysis indicates humans and marmosets undergo a pronounced post-birth brain growth spurt that aligns with early vocal-learning milestones, unlike chimpanzees and macaques.
• Earlier marmoset experiments show infants receiving frequent adult responses during babbling learn adult-like calls significantly faster than control groups.
• A simplified mathematical model demonstrates how rapid neural maturation coupled with social feedback can set conditions for subsequent vocal-skill development.
• The researchers plan follow-up studies to assess whether adult marmosets use infant-directed vocal patterns analogous to human baby talk.