In the water-level task, both spatial skill and physical knowledge contribute to representing the surface of a liquid as horizontal irrespective of the container's tilt. Under the standard visual format of the task, men systematically surpass women at drawing correct water lines in outlines of tilted containers. The present exploratory experiments in haptic conditions supplemented with facilitating postural requirements attempted to eliminate this gender difference: The stimuli being screened from view, gravity cues were supplied through the necessity to regulate body and arm posture. In Experiment 1, the participants stood in an unstable posture to complete a haptic version of the task in which they touched vertically set stimuli with unsupported arm movements. The control (standard) condition involved the visual format: The seated participants were presented with horizontally set stimuli that allowed full arm support. The male advantage was manifest in the control condition, whereas, in the experimental condition, women outscored men on the first half of the problems. As it appeared that maintaining the unstable posture might have been more disruptive for men, in Experiment 2 the participants sat to perform the haptic task with vertically set stimuli. Their performances replicated those recorded under the experimental condition in Experiment 1. However, within a subgroup who knew about the invariant orientation of liquid surfaces, women's proficiency exceeded that of men in the experimental condition. Overall, these results support the idea that, with nonvisible stimuli, women gain from haptic and proprioceptive information reducing the saliency of the container's shape and orientation, which are misleading references in the case of visible stimuli.
Robert, Michele and Longpre, Sophie
"Sensory and Postural Input in the Occurence of a Gender Difference in Orienting Liquid Surfaces,"
The Psychological Record: Vol. 55
, Article 3.
Available at: http://opensiuc.lib.siu.edu/tpr/vol55/iss1/3