Data from a study by Savage‐Rumbaugh and colleagues on comprehension of spoken English requests by a bonobo (Kanzi) and a human infant (Alia) supports Fitch's hypothesis that humans exhibit dendrophilia, or a propensity to manipulate tree structures, to a greater extent than other species. However, findings from language acquisition suggest that human infants do not show an initial preference for certain hierarchical syntactic structures. Infants are slow to acquire and generalize the structures in question, but they can eventually do so. Kanzi, in contrast, is dendrophobic: even though his non‐hierarchical strategy impairs comprehension, he never acquires the hierarchical structure.