This is all IMO
genetics and your physiological make up. Other things I am sure can increase it, if you have an issue with higher estrogen, and hop on a cycle, your gyno bound.
That being said some guys naturally have more estrogen than others. Some guys also have slight gyno from puberty. Alot of it just depends on your bodies natural tendencies, I dont think drinking contributes though it is stupid to do on cycle. Age Can factor in, I am seeing more issues from younger guys on here than older. but that could be due to the fact that the older gents are a bit more educated on the subject often times or at least have learned from when they are younger.
It almost seems hit or miss, but it really just depends. Also it varies on the compound, such as possibly prolactin gyno or estrogen gyno. Know the compound you take and its risks. Serms and other PCT and support products make a world of differance and can even combat/stop/reverse early gyno.
Nolva
Clomid
Torem
Adex
Caber
Those SERMs and other aids(such as adex being a potent potent AI) are prescription only usually. But if you wanted to test some on some rats or hamsters, you could investigate acquiring some Research Chemicals to do so.
I think the biggest reason I see on here for gyno is unpreparedness. Though sometimes its a complete fluke and random, such as delayed gyno.
This is all IMO, i could be wrong on some of it. And there will be others smarter about it than me chime in.