Toshitaka N. Suzuki, Yui K. Matsumoto

It has been hypothesized that the generative power of language stems from a cognitive capacity called “Merge,” which enables senders to combine two linguistic items (e.g., two words or two phrases) into a sequence and receivers to recognize it as a single unit (Chomsky, 1995, 2001). In an experimental study published in Nature Communications (Suzuki and Matsumoto, 2022), we demonstrated that a bird species, the Japanese tit (Parus minor), has evolved “core-Merge,” the most fundamental form of Merge that combines two words into a single unit (Fujita, 2009, 2014). In their recent publication in Frontiers in Psychology, Beckers et al. (2024) raised concerns about the interpretation of our results. However, after careful consideration, we maintain the conclusion that our results provide evidence for core-Merge.