Sound symbolism, the surprising semantic relationship between meaningless pseudowords (e.g., 'maluma', 'takete') and abstract (round vs. sharp) shapes, is a hitherto unexplained human-specific knowledge domain. Here we explore whether abstract sound symbolic links can be explained by those between the sounds and shapes of bodily actions. To this end, we asked human subjects to match pseudowords with abstract shapes and, in a different experimental block, the sounds of actions with the shapes of the trajectories of the actions causing these same sounds. Crucially, both conditions were also crossed. Our findings reveal concordant matching in the sound symbolic and action domains, and, importantly, significant correlations between them. We conclude that the sound symbolic knowledge interlinking speech sounds and abstract shapes is explained by audiovisual information immanent to action experience along with acoustic similarities between speech and action sounds. These results demonstrate a fundamental role of action knowledge for abstract sound symbolism, which may have been key to human symbol-manipulation ability. Sound symbolism is an umbrella term that covers the non-arbitrary associations between meaningless speech sounds and sensory or other meanings 1 (for a review see 2). The iconic links between pseudowords and abstract visual shapes is the most popular demonstration of this phenomenon. In the present study, the term "sound symbolism" will refer to these latter associations. In his seminal book entitled "Gestalt Psychology", Köhler 3 described the classic "maluma-takete" paradigm in which humans match a round figure to a 'round' sounding pseudoword, such as "maluma", and a sharp figure to a 'sharp' sounding pseudoword such as "takete", thus presupposing an abstract 'resemblance' between the otherwise meaningless symbol (pseudoword) and the corresponding shape, possibly based on shared modality general abstract properties. Many experimental studies confirmed Köhler's example and demonstrated the postulated iconic speech-sound/meaning mappings across languages 4-6 , even at early age (for a meta-analysis see 7) and across stimulus modalities 8,9. Furthermore, the ability to perform well on sound symbolic tasks has been related to word learning capacity in young children 10-12. These results led to some skepticism towards the linguistic Saussurean 13 position that the relationship between form and meaning of signs is arbitrary and even suggest an important role of sound symbolic mechanisms in language development 14 and evolution 15. Specifically, vocal iconic mappings between infants' first spoken words and the referents these words are used to speak about appear to be substantial, so that iconic signs may have a special status for our ability to talk about things not present in the environment, a feature sometimes called 'displacement in communication' 6. Today, iconicity and sound symbolism along with their bootstrapping role in language development and evolution are widely upon agreement 15 , with recent e...