Put simply... If it ain't RP, it ain't happening. I have joined a few groups that seemingly recruit just for the fun of speaking with a group of the same species as their character, and I must say it can get boring quick. I'll get down to the solution right away then; ask around your group for members like you wanting to RP. Then, head a little ways away from the social chatter-boxes and just RP without them. From my personal experiences, I've found that if you stay within local range of each other eventually something will be said that entices another member to join in. Then another, and another, and maybe even the leader will join in. Truth is; people like to do similar things with each other. If one group sees people RolePlaying something that interests them, more than likely they'll join in the fun c: