Lateralization of conspecific vocalization has been observed in several vertebrate species but a systematic integration of these results across orders was lacking so far. Biopsychologists from Bochum now used cladographic comparisons to identify those vertebrate orders in which evidence for or against lateralization of conspecific vocalization has been reported, and those orders in which further research is necessary. The analysis showed that there is evidence for lateralization of conspecific vocalization in several mammalian orders (e.g. Primates) and also evidence for lateralization of conspecific vocalization in some avian species (e.g. within the Passeriformes order). While especially the primate data suggest that human language lateralization could have resulted from an inherited dominance of the left hemisphere for those neural properties of language that are shared with the sensory or motor aspects of vocalizations in other vertebrate species, it becomes clear that this conclusion presently is supported by only sparse empirical evidence. The majority of vertebrate orders, especially among non-amniotes, still need to be explored.

Ocklenburg, S., Ströckens, F., Güntürkün, O. (2013). Lateralisation of conspecific vocalisation in non-human vertebrates. Laterality, 18, 1-31.