This article by Norlander ^[1] specifically studies the relationship between moderate alcohol consumption (1.0ml/kg body weight) and creativity. According to my very rough calculations, this would correspond to a BAC ^[2] in the range of 0.12–0.14 for a 73kg human. The paper concludes

...modest alcohol consumption inhibits aspects of creativity based mainly on the secondary process (preparation, certain parts of illumination, and verification), and disinhibits those based mainly on the primary process (incubation, certain parts of illumination, and restitution).

In other words, moderate alcohol consumption does improve certain types of creative thinking, while inhibiting other types of creative thinking. Since the skills required for computer programming are solely cognitive in nature (discounting the motor skills required to type, of course), and given that creativity is a large part of computer programming, it is at least plausible that one might gain some amount of improvement from alcohol consumption.

There have also been studies on the relationship between alcohol consumption and creative output ^[3]. That study examined 34 well known, heavy drinking, 20^th century writers, artists, and composers/performers. It concludes:

Analysis of this information yielded a number of interesting findings. Alcohol use proved detrimental to productivity in over 75% of the sample, especially in the latter phases of their drinking careers. However, it appeared to provide direct benefit for about 9% of the sample, indirect benefit for 50% and no appreciable effect for 40% at different times in their lives. Creative activity, conversely, can also affect drinking behavior, leading, for instance, to increased alcohol consumption in over 30% of the sample. Because of the complexities of this relationship, no simplistic conclusions are possible.

So for a small portion of people there was a notable increase in creative output as a result of alcohol intake. It does appear that the study did not control for the quantity of alcohol intake, though, so this may not be directly applicable to the Ballmer Peak.

The best study I was able to find on the subject was by Lapp, Collins, and Izzo ^[4]. They gave subjects vodka tonics of varying strengths (by varying the ratio of tonic to vodka), some of which did not even contain any alcohol. The subjects believed that they were drinking a standard-strength vodka tonic. The subjects then were asked to perform a number of cognitively and creatively challenging tasks. Here is what they conclude:

The present results support the idea that creative people probably gain inspriation from consuming alcohol ..., but show that this effect may be due to the expected rather than the pharmacological effects of the drug. ... A convergence of evidence supported the idea that creativity is enhanced (at least in some aspects) by the expected effects of alcohol.

In other words, alcohol can improve certain aspects of one's cognitive ability, but this effect is not likely due to any pharmacological process (i.e., it is often sufficient to merely believe that one is drinking alcohol in order to achieve the same benefit).

And remember: The Ballmer Peak, as it is currently understood, is but a two dimensional projection of what in reality is a higher dimensional space, vi&.,

;-)

New study at the University of Illinois at Chicago reported by Medical daily: Drinking Alcohol May Significantly Enhance Problem Solving Skills ^[1]

Scientists found that men who drank two pints of beer or two glasses of wine before solving brain teasers were quicker in delivering correct answers.

Here is the related scientific publication

Highlights

• We examine the effects of alcohol intoxication on creative problem solving.
• Sober and intoxicated (BAC = .075) individuals solved Remote Associates Test items.
• Intoxicated individuals solved more items in a shorter time compared to sober.
• Intoxicated individuals were more likely to rate their solutions as insightful.

— Uncorking the muse: Alcohol intoxication facilitates creative problem solving ^[2] by Andrew F. Jarosz, , Gregory J.H. Colflesh , Jennifer Wiley

If we think about driving a car, it is generally agreed that there is no alcohol level at which one is a better driver than when one is sober. This document ^[1] lists some of the findings:

Behavioural studies suggest that driving related skills are significantly impaired at blood alcohol concentrations below 10-9 mmol/l and that little evidence exists for a threshold below which driving related skills are unimpaired.

(Alcohol does of course impair judgement, so it is likely that there is an alcohol level at which one believes one is a better driver, even though one isn't.)

Computer programming is a significantly more demanding task than driving a car, and it is extremely unlikely that there is any level of alcohol at which one is really a better programmer than when one is sober.

The Observer ^[1] reports on a study showing it is real.

A recent study at the University of Illinois tested the creative problem solving ability of a group of men who were given vodka cranberry and snacks and asked to solve brain teasers. The results were starkly different for the tispy group, which had a blood alcohol concentration level of 0.075, versus the control group:

Astonishingly, those in the drinking group averaged nine correct questions to the six answers correct by the non-drinking group. It also took drunk men 11.5 seconds to answer a question, whereas non-drunk men needed 15.2 seconds to think. Both groups had comparable results on a similar exam before the alcohol consumption began.