For those who have worked in a liquor store, is there an unwritten rule that some drinks incur less ID checks than others?

Before I continue, I’m a month shy of 23, and do not encourage underage purchases; this is merely my observations of getting ID’d in liquor stores based on what I’m buying. I’d say no matter what I’m buying, there’s probably a 50/50 chance that someone asks for my ID in a liquor store. What I have noticed, however, is that when I buy packs of canned beer, or any of the trendier party liquor (tequila, vodka, etc.), the probability that I’ll get asked for ID is maybe 60-70% likely. Brown liquor depends; if it’s American whiskey, the odds are maybe 30% I’ll get asked, for scotch I haven’t noticed too many requests. When I buy my favorite dessert wine, Taylor’s port, I NEVER get asked to show ID.

Are employees at liquor stores trained to identify what I call “frat drinks,” and be more rigid in asking to show ID, or is it probably just subconscious age profiling? These aren’t complaints; I’m just curious about these observations.