<snip of consuming the same volume of alcohol in beer vs 'hard liquor'>

I've always heard this, and it makes sense; and it's what I was taught in
drug/alcohol awareness class in school as a teen.  But I long felt my
experience differed from this, and years ago when I found myself with a long
string of Friday nights with nothing better to do, I conducted a little
semi-scientific experiment:

On Friday evening at the same time each week I would have the same frozen
dinner, so I had the same thing on my stomach.  Then I would begin drinking
one selected type of alcoholic drink each week - beer one Friday, wine the
next, vodka the week after that, and so on.

I used a bartender's guide for mixed drinks and measured carefully, sizing
each drink so I got the same amount of alcohol per drink.  I had a friend
once who insisted he could safely drink one beer per half-hour without
getting drunk, and my aim was to become intoxicated, so I timed myself to
have one drink per twenty minutes, drinking it over the twenty minute
period, and then starting the next.

After each drink, I sat down at my computer and played a couple of simple
computer games.  One was a 'Concentration' type game, to measure my ability
to focus and remember things.  The other measured my response time in
thousandths of a second - it flashed a light and I hit a key, and it told me
how long it took me to respond.  I also wrote down generally how I was
feeling.

The overall results were similar for most drinks - my scores on the games
went up for about the first three drinks each evening, usually, I assume
because the alcohol was relaxing me, but perhaps the alcohol wasn't having
much effect and I was just getting into the rhythm of the games.  After six
drinks, my scores plummeted (and six drinks, in my experience, is the point
at which I begin to have a hangover the next morning, whatever I'm
drinking).

But the 'curve' of my response to different types of alcohol was different.
I've long since lost the actual data I recorded, but IIRC, with vodka (and
tonic), and rum (with caffeine-free Coca-Cola), my 'improvement' in the
reaction scores to the games increased the most, stayed steady through drink
four and had a moderate drop for drinks five and six; I was also less aware
of 'feeling drunk' even when I was, with vodka.  Beer had less effect
through the first three or four, but a more noticeable drop from five and
six; beer also made me sleepy.  Wine had a very gentle curve (as befits a
genteel beverage, I suppose!) - not much change for the first few drinks and
a more gradual decline after six glasses.

The last alcoholic beverage of my experiment was tequila.  I followed the
bartending guide for frozen margaritas, calculated a 'one-dose of alcohol'
serving size, mixed them up and found them to strong for my liking, so I
diluted them a bit and recalculated... than I had about a drink and a half
and curled up on the sofa and slept it off.

I wasn't up to drinking straight vodka, whiskey or rum, and I don't know
what effects other components of the drinks have - sugar in the vodka and
rum drinks might effect the body along with the alcohol; caffeine (I avoided
for the sake of my experiment in my Rum-&-Coke) might speed up metabolism of
the alcohol; I've heard it's the carbohydrates in beer that make one sleepy,
but that doesn't sound right to me.  I seldom drink hard liquor anymore, and
never more than one or two drinks in an evening, and wine I most often drink
with meals, influencing its effects. But I still notice a different effects
from different kinds of alcoholic beverages.