Keith, I have to say that "Gaussian Distributions", "Bell-Shaped Curve", and the "80-20 Rule" have all had a terrible effect on people's decision making. They are mental crutches that lead to serious mistakes.
I have spent a lot of my life in business hunting out the opportunities at the profitable end of what folks think is a Gaussian distribution of outcomes (in this case potential upside for a deal). Anyone who does venture investing rapidly learns that the 80/20 rule does NOT apply to deals. Over 50 years of data from the firm I used to work with showed that across all our investments 2% of the deals provided 98% of the profits. The partners would consider you a dolt if you said something like "80/20 rule" when talking about results.
I'm sure you know that one of the other fields where this sort of thinking results in terrible decisions is in evaluating the performance of technical people, specifically programmers. IBM ran a massive study of their programmers' productivity in the '70s and again in the '80s. Both times they discovered that the spread of productivity amongst programmers was over 75:1, as Dr. Thompson of IBM said in a public speech:
A quote from memory: "Because we are unable to hire the absolute best programmers, they typically move into academia (EG: Knuth), and we try hard not to hire the below-average programmer, our research supports an estimate that the range of productivity in the pool of all trained programmers is over 115:1. This means that our ability to forecast the delivery of new software could have a margin of error of greater than 50:1. Said another way, if one doesn't track programmer productivity, then a project could take between one year and over 20 years depending upon the programmer to whom it was assigned. Moreover, we have absolutely no evidence that productivity correlates with any sex or race. The good news is that well documented highly productive programmers tend to continue to perform at breathtaking levels, but that they lose that ability during their later years. "
You could have heard a pin drop as he delivered that report. To this day, I've seen no evidence to show that people's ability to program has become more uniform. There is still at least a 50:1 observable difference, and many believe it's more like 100:1. Understanding how fat the tail is matters a tremendous amount, as does how far from the center of the "bell-shaped curve" that tail really goes.
Of course, that's what makes investing in and managing people so much fun. It's all about being better than the competition at finding those who are truly outstanding.
It also leads you to conclude that we're doing something very wrong if we have a 3:1 difference in pay for a 50:1 difference in performance. Yet, it's socially very hard to have more than a 4:1 difference in pay for the "same job". Sadly, this means that the "pay" is attached to the "job" and not to the "productivity." Thus, the ongoing opportunity for investors to motivate the extreme top end of the distribution to break out on their own so that they can early what they deserve based on productivity vs job title. (probably stating the obvious above, sorry about that.)