I am constantly finding Carmen and Scooby less than an inch apart, so I'd say they socialize. I'd like to have enough cresties (and money) to try housing a small colony in a cage like one of the big chameleon cages and see what social behavior there may be to observe. Unfortunately, that's not an option at the moment, but if I were going to house a pair of males together, I think I'd try to go for a minimum of the size you suggested, or even bigger like the 100 gallon Apogee reptarium (lining 3 sides w/ Glad Press 'n' Seal, probably).