Another reason why adults find it hard to draw accurately.

Misperception of objects is a major cause of inaccuracies in adults' drawing. It has previously been established that participants' drawings are biased by their knowledge of the drawn object. We hypothesised that additional inaccuracy arises because drawings are biased towards participants' idiosyncratic canonical representations of the object. We report that participants' free drawings of a cylinder are correlated with their observational drawings of the same shape, providing evidence that people's observational drawings are distorted by their individual schematic representations of the objects in question. It is unclear whether this reflects a perceptual distortion or a bias in drawing production; in either case, this result provides a further explanation why people are poor at drawing from observation.