Does beer cause more fatigue than liquor? These days I drink almost as much liquor as I do beer, and it seems like beer more commonly causes sleepiness and fatigue, where liquor gives a straight up 'drunken' effect.

I wonder, though, is this actually the case or is my perception of the two drinks a self fulfilling prophecy?
It could definitely be a perception thing or any difference with the situation in which you consume beer vs liquor.  (IE, if you're drinking a lot of Jack and Coke maybe that caffeine is helping keep you alert?)

I think the most compelling answer is that there's actually a decent amount of research that shows hop compounds actually have a slightly sedative effect, especially in conjunction with alcohol.  So...you know, beer.

Some sources:

National Institute of Health: The concentration of 2 mg of hop extract effectively decreased nocturnal activity in the circadian activity rhythm.

WebMD (Look under "Interactions"): Alcohol can cause sleepiness and drowsiness. Hops might also cause sleepiness and drowsiness. Taking large amounts of hops along with alcohol might cause too much sleepiness.