I can see how I gave that impression. I should have worded it better.
Any group of individuals who share a common experience or a common history will share common characteristics. As you point out, certain Asian groups perform better academically than average because their culture demands it. Certain African populations perform better athletically than average because their population has selected for it.
Not only do certain Asian groups perform better academically, but they have better life outcomes (if we're using the metric that higher income = better outcome). Certain characteristics (such as promotion of a work ethic, or, conversely, a culture which does not place emphasis on work ethic) will have a strong correlation to outcomes.
The same applies for health outcomes. If a certain culture promotes a healthy diet and exercise and another culture doesn't emphasize these things (and tends toward things like fast foods and sugary snacks), you should expect different health outcomes for those groups. Overall health outcomes should vary based on the characteristics (especially those that reflect in diet and activity) with no external bias.
But that's not the same as success in life. I am good at maths and science and hopeless at athletics. A friend of mine is the opposite, he's good at athletics and hopeless at maths and science. But we are both successful in life. It's not the characteristics of the group that's the problem, but the outcomes of the group. For example: If members of one group is incarcerated five times as often as the members of another, then there is a problem beyond the group and its characteristics. The same applies for health outcomes. (Assuming that the group isn't self selecting for health problems: Obviously a group of Down syndrome individuals would fair worse health wise than the average.) Also it seems clear that the health issues of different groups would most likely be different in nature (not in severity), but the overall health outcomes should be very similar for each group, unless there was some external bias.
I'd wager that a part of the reason of the success of you and your friend is that you both probably have a good work ethic and place a high value on effort. I'd also say that the outcomes of two individuals is hardly reflective of social demographic trends.
There is sometimes difficulty separating outcomes and characteristics. I think the best example of this is generational racism. If a group has been deprived of good education for generations solely on the basis of their race (which has happened here in Australia), then this will show up in their characteristics. Poor knowledge and poor reasoning skills will show up as a characteristic. But it's not an intrinsic characteristic. It is one that has been foisted on them from outside their group, and therefore it is actually an external bias.
While outcomes and characteristics are not the same thing, they can (and often do) have a correlation.
I'm not arguing that all characteristics are intrinsic. However differences in characteristics are not necessarily "foisted on them from outside of their groups". Plenty of different social groups, historically, have placed different emphasis on different traits, and unless you don't believe in the theory of natural selections, you should expect different characteristics - and outcomes to arise over time.
I agree that generational racism is real, and that past racial bias impacts current outcomes based on cumulative effect (such as poor education being deprived for a particular racial group).
I'd put it slightly differently:
"Systematic bias is one of the major reasons for significant outcome differences between different groups within any society"
I'd put it differently, myself:
"Systemic bias is one of the many reasons for significant outcome differences between different groups within any society. The impact of societal bias varies widely, and is often difficult to isolate."
It's interesting that you start arguing from the aspect of characteristics and end up talking about outcomes. You do it seamlessly as though they are the same thing. They are not. Yes, different groups may have different characteristics, but the outcomes of each group should be similar. If they are not, then there is a clear reason (eg: my Down syndrome example) or there is some external bias occurring. In both cases we should address the problem; this is why we have affirmative action, anti discrimination laws, and accessibility regulations. .
It's interesting that you (and some others I've had these types of discussions with) will concede that racial groups do, indeed, have different characteristics, but will, in the same breadth, deny that different characteristics are likely to lead to different outcomes. No, they are not the same, but, yes, they do have a correlation.
Again, I take you back to the example of Asians achieving better outcomes than whites. Unless you're arguing that their better outcomes are a result of racial bias in their favor, then you have to reach the conclusion that their better outcomes are a result of their different characteristics.
Arguing that "different groups should have similar outcomes, regardless of characteristics" is a baseless assertion, and not reflected within or between different racial/social groups.
