I've seen a number of folks discussing the faults of differentiating ability score ranges between male and female characters in role playing games this week. A much more interesting question to me is whether we should consider creating distinctions between culture groups in a human centric world. AD&D, for instance, has no problem applying ability score adjustments to the demi human races when compared to humans.
Consider that one of the most common themes in Swords & Sorcery literature is the strong but primitive barbarian juxtaposed against the decadent cultures of the large cities. The barbarian character is invariably more physically capable and resolute than his civilized antagonists. You see this motif in the RE Howard stories of Conan, the character of Fafhrd in the Lankhmar stories, and countless other stories featuring rugged, sword-wielding barbarians.
Consider also this historical excerpt from Tacitus's Germania, speaking of the many tribal inhabitants across the Rhine:
Hence the physical type, if one may generalize at all about so vast a population, is everywhere the same wild, blue eyes, reddish hair and huge frames that excel only in violent effort. They have no corresponding power to endure hard work and exertion, and have little capacity to bear thirst and heat; but their climate and soil have taught them to bear cold and hunger.
My intent isn't to start a real world furor over Tactitus's text; it's been abused by plenty of folks already (koff, Nazis, koff) in other contexts. But when you're making a game world that features humans from different cultural groups, does it make sense to have racial or cultural abilities that differentiate those groups mechanically in game terms?
My son is playing a lot of the Skyrim game, and he tells me "Nords", the Skyrim analog of the northern barbarians, are tough and resistant to cold. That sounds a bit like Tacitus's description of the barbarians in Germania. Video game designers apparently don't have any problems making humans from different areas different from each other based on culture or race.
Let's look at these big blonde northerners again. According to Tacitus, they're all pretty much big and strong. The fantasy stereotype of the barbarian is also strength; what's the argument against giving characters from barbarian lands a +1 to the strength score?
But how about a -1 to the intelligence? You know, to balance it out. The way I read the intelligence tables in D&D, intelligence gives you literacy, knowledge of extra languages, and the ability to learn spells - all capabilities that are the result of education and not primarily aptitude. There shouldn't be a problem declaring that characters living out in the untamed wilderness, as an insular tribal unit, haven't had the same education as the decadent urbanites - but the moment you tack a -1 intelligence onto a cultural group, you step onto a pretty slippery slope my friend. Even if it is a fantasy culture. Would Conan put up with a -1 to *his* Intelligence score? You don't tug on Superman's cape, or call a Cimmerian uneducated or stupid. The Romans may have looked down on the barbarians, but who had the last laugh? (Alaric did).
I'm only familiar with one official D&D supplement that tackled human racial and cultural differences - it was the Hollow World boxed set for classic D&D / Mystara. The Hollow World gave humans from different ethnic groups pseudo skills and proficiencies to differentiate their culture backgrounds. Antalians (the Viking analog) could climb like thieves; Milenians (ancient Greeks) all had extra bonuses with spears. Some of them were more extreme; Tanagoro tribes people (analogs for African cultures) could all move at 150' base movement. Azcans (the Aztec knock offs) were ridiculously tough and got an entire extra hit die at level 1!
What's my point? In today's day and age, humans are uncomfortable declaring another group diminished in any capacity. Maybe games have no place classifying differences between groups of people (or the sexes) in this way. But there's a cynical side of me that sees a really simple way around the problem. Just flip it around and highlight a positive benefit, and cultural differentiation becomes much less controversial (and judgmental). "Scythians and Parthians don't get minuses when firing from horseback!", that kind of thing. Make people feel good about the in-game differences.
Hey, look at what I just did? I managed to justify giving all those barbarian tribesman a +1 to their strength scores after all. I feel better already.