I don't think you know what a conspiracy is. People don't speak up precisely because they are alone and don't want to be shunned by the echo chamber. If you've heard about it so many times, why do you think you know best and deny the observations of others?
I also happen to work with biologists and I found no such thing as you describe. People aren't afraid to talk about sex differences. There's no hidden truth that everyone speaks in undertones about and is scared of mouthing out loud. People don't mindlessly transpose what they know about their model organisms to humans. People don't buy into evopsych crap either. (There's a reason evopsych papers have trouble even making it into PNAS.) The community isn't filled with Damores either. So maybe you could clarify what you're talking about because I seem to have lost you there.