I told him that it was only an anecdote, and I felt that alcohol was alcohol, and your brain didn't care where it came from.
What say you all?
I don't have any studies handy to link to, as I'm relying on my own past reading; but all alcohol is
not the same. For starters, every alcoholic beverage is going to come with other substances besides the ethanol: water, sugars, flavouring agents, and various other alcohols. The water content alone can be enough to alter one's behaviour and reaction; as it will regulate the speed of absorption. What food you eat will also have a profound effect, but for this purpose I'm assuming that to be equal for all alcoholic beverages.
The sugar content will definitely affect not only how the alcohol is absorbed, but the sugar will also affect body chemistry and mood.
Flavouring agents can have significant effects, depending on the individual reactions; but for most distilled alcoholic drinks, except in terms of allergies, these will typically be minimal. Liquers and non-distilled drinks may have more of these, and they may have a more profound effect, but the sugar content is likely to be more significant. Vanilloids from aging in wood are the most likely to have some effect, depending on concentration.
Other alcohols are a major factor in the effect of many drinks. In the brewing/distillation industry these are known as "congeners", and typically consist of trace amounts of methanol, fusel alcohols, and acetone. The higher the level of these congeners, the stronger the effect they will have; and can certainly alter the effect of the ethanol, creating "mean" or "happy" or whatever drunks. The percentage of congeners is entirely the result of the substance fermented, and the distillation technique for "hard" liquor; and is due to the amount of pectin and certain other non-simple-sugar fermentables. Grains produce little or no congeners when fermented; while fruits and vegetable substances produce more. Primitive distillation processes, particularly freeze distillation, can concentrate these congeners to potentially toxic levels. Even good distillation process does not necessarily remove all of them, because many have vapour points similar to ethanol.
Pure grain drinks like vodka, Everclear, and whiskey are likely to have a much different effect from fruit or vegetable-based drinks like tequila, grappa, or rum.