Research has documented systematic articulation differences in young children’s first signs compared with the adult input. Explanations range from the implementation of phonological processes, cognitive limitations and motor immaturity. One way of disentangling these possible explanations is to investigate signing articulation in adults who do not know any sign language but have mature cognitive and motor development. Some preliminary observations are provided on signing accuracy in a group of adults using a sign repetition methodology. Adults make the most errors with marked handshapes and produce movement and location errors akin to those reported for child signers. Secondly, there are both positive and negative influences of sign iconicity on sign repetition in adults. Possible reasons are discussed for these iconicity effects based on gesture.