I was just thinking about this the other day, and concluded that were I to start a new game I’d lay it out to players per the bullets below. Note that this is my categorization, and may not match up with how other’s see it. But perhaps if others disagree they could propose their own added detail.
• The categories below are for the entire adult population of humans. Some are spread very randomly throughout the population (such as willpower), while others may skew off centre for certain demographics (i.e. men tend to have higher bodies than women, young men in particular are more apt to have higher strength, while reactions and agility tend to fade with age so average higher in the young and lower in the older. In other words, it is not that surprising that a lot of grunts have fours in most of their physical stats.)
• Three is not only the average, it is the score that close to two-thirds of people lie for any given stat.
• Two and four are still reasonably common, about one person in seven will fall into each of those. When you know a person with a stat in this area, you know they are good or bad in that area. They are the klutz in your group, or the one always has their taxes in early, etc.
• One and five are rare, and the extremes of what you will encounter day-to-day. Only about two or three percent of people fall into each of those. Scores of one represent significant trouble with what should be mundane tasks, scores of five mean you are quite noticeably better than most people in that area, and can improvise in that area with little odds of screwing up. Even casual interaction with such people tends to make it apparent that they are unusual. Indeed, when it comes to body or strength one can usually tell at a glance.
• Zero and six are very rare in the population, only one or two in a thousand. Zero is so bad that you’ll never see a shadowrunner with that stat, because the person is fundamentally not competent (imminent risk of death, tremors so bad they can’t walk or use tools, seriously mentally disabled, etc.) A six is professional athlete level of physical prowess, star performer level of charisma, gifted detective level of intuition, etc.
• With exceptional attribute, a few people will have a seven. At this level one can become well known if they are so inclined and have complimentary abilities. These are the strong men who pull semi-trailers, the renowned scientists, athletes who spend years at the top of their sport, actors who you will pay to go see without caring about the nature of the show they are in, etc. In theory there would be an equivalent level of negative attribute, but such people never leave high care institutions (if they survive to adulthood at all) because they are fundamentally non-functional (completely non-verbal, surviving on a respirator, very frequent and severe seizures, etc).
• For meta-humans, the percentages adjust based on the stat value (i.e. about two thirds of dwarves have a willpower of four while only two to three percent have a willpower of two), however you compare the ability to human levels based on the average stat (i.e. the ‘average’ (willpower=4) dwarf always had homework done on time and always installs the security patches on their commlink). Yes when you look at what this means, dwarves and orcs are pretty scary strong, and trolls are in a whole other league when it comes to body and strength – just as we wouldn’t normally compare human size and strength to that of a polar bear .