Watson, L. M. 2010. Effectiveness of perforated plexiglass dividers as social grooming devices between neighboring, individually housed adult male Macaca fascicularis. Laboratory Primate Newsletter 49(4), 1-4.

A clear, perforated, plexiglass divider was installed between neighboring cynos to test whether it altered their proximity to one another, or prompted any behavioral changes. ... Adult male cynomolgus monkeys tend not to spend a large amount of time in close proximity to one another in the wild, nor in other settings (van Noordwijk & van Schaik, 1985). This lack of close proximity was reflected in the outcome of the present investigation, regardless of whether the mesh or the plexiglass divider was in place. Although several pairs showed some changes in relative location in their cages when the mesh vs. the plexiglass was present, overall there was not a significant tendency to be closer to each other with the plexiglass.