Firstly, the data is clearly not exhaustive and thus it was not possible to draw any conclusions about differences in penile size between the races. As you have admitted, the data is limited. As such, it certainly cannot be taken to be conclusive evidence. Even based on the Appendix which you attached (which relies on old data), there is a high degree of variability within races, which shows that racial differences are less important than differences between individuals.
You shifted your claim to uncertainty, I do not challenge the uncertainty, and I am done talking about penises. Not that it isn't interesting. You have some peculiar ideas about why modern people don't like small dicks, and I prefer to let that stand. The conversation may devolve into lowbrow ridicule.
Anyway, even if your conclusion were true, we don't know what causes the variation in penis sizes - even if there is a (partial) genetic cause, there is likely to be an environmental factor as well. Consider height: it was believed for a long time that height was genetic but we now know that nutrition significantly affects height (
https://ourworldindata.org/human-height).
Variation of height within groups is about 90% genetic. We know this from twin and adoption studies, and the value does not change even after we know that the average height all over the world has risen drastically over the last hundred years or so. It is one of many large secular changes of polygenic traits, including intelligence and lifespan, but height is the most obvious such trait, and I don't think the puzzle can be resolved with the 10% remainder. The only way to explain it all, in my opinion, is with epigenetics in response to the newly safe and plentiful environments. It is still about genetics, but the changed environments triggered secular changes of the genetic expressions, which I expect is an evolutionary mechanism that enables hasty adaptation to a changed environment. It is just my own hypothesis, and I think it is a pretty good one.
As regards IQ, it is dangerous to presume that just because a group has a lower average IQ, then the cause of that lower average IQ is genetic. The people who push this ideology are not trying to improve the IQs of Africans (even though IQ is at least partially environmentally caused). They are trying to justify discrimination against Africans (and other races which they believe are lesser) instead. Led to its logical extreme, this would mean the justification of atrocities like genocide and slavery against fellow human beings. I have yet to see any believer in racism (scientific or otherwise) try to find a way to improve the lot of races which they believe are lesser than their own (e.g. funding education for the races which are of lower IQ so they can at least reach their maximum potential IQ). That's because racists are interested in nothing more than preserving unfair advantages which have accrued to their race, which they cannot justify except by resorting to racism.
I mostly agree. One way or the other, racists are interested in either preserving advantage or bringing advantage to their own race, and there is a strong popular link between that sort of racism and the "scientific racism" which holds that one race's average IQ is different from another because of genetics. You really have to go far out of your way to find some people who believe one and not the other. Those people would be the psychologists who specialize in human intelligence. For an example, I suggest the 2017 book by Richard Haier,
The Neuroscience of Intelligence. In Chapter 6 he wrote his opinions on the realities of intelligence differences as follows:
What are the possible policy implications of introducing neurobiology perspectives to research on these problems? Not all individuals have a pattern of cognitive strengths that allow barely minimum success in modern, complex society. This is evident with respect to g and other factors of intelligence. To the extent that different patterns of cognitive strengths and weaknesses are rooted more in neurobiology and genetics than in childhood experience, it is incorrect to blame lack of economic or educational success entirely on poor motivation, poor education, or other social factors. All these things matter, but with respect to intelligence, they do not appear to matter that much, as the weight of evidence indicates.
Here is my political bias. I believe government has a proper role, and a moral imperative, to provide resources for people who lack the cognitive capabilities required for education, jobs, and other opportunities that lead to economic success and increased SES. This goes beyond providing economic opportunities that might be unrealistic for individuals lacking the requisite mental abilities. It goes beyond demanding more complex thinking and higher expectations for every student irrespective of their capabilities (a demand that is likely to accentuate cognitive gaps). It even goes beyond supporting programs for early childhood education, jobs training, affordable childcare, food assistance, and access to higher education. There is no compelling evidence that any of these things increase intelligence, but I support all these efforts because they will help many people advance in other ways and because they are the right thing to do. However, even if this support becomes widely available, there will be many people at the lower end of the g-distribution who do not benefit very much, despite best efforts. Recall from Chapter 1 that the normal distribution of IQ scores with a mean of 100 and a standard deviation of 15 estimates that 16% of people will score below an IQ of 85 (the minimum for military service in the USA). In the USA, about 51 million people have IQs lower than 85 through no fault of their own. There are many useful, affirming jobs available for these individuals, usually at low wages, but generally they are not strong candidates for college or for technical training in many vocational areas. Sometimes they are referred to as a permanent underclass, although this term is hardly ever explicitly defined by low intelligence. Poverty and near-poverty for them is a condition that may have some roots in the neurobiology of intelligence beyond anyone’s control.
The sentence you just read is the most provocative sentence in this book. It may be a profoundly inconvenient truth or profoundly wrong. But if scientific data support the concept, is that not a jarring reason to fund supportive programs that do not stigmatize people as lazy or unworthy? Is that not a reason to prioritize neuroscience research on intelligence and how to enhance it? The term “neuro-poverty” is meant to focus on those aspects of poverty that result mostly from the genetic aspects of intelligence. The term may overstate the case. It is a hard and uncomfortable concept, but I hope it gets your attention. This book argues that intelligence is strongly rooted in neurobiology. To the extent that intelligence is a major contributing factor for managing daily life and increasing the probability of life success, neuro-poverty is a concept to consider when thinking about how to ameliorate the serious problems associated with tangible cognitive limitations that characterize many individuals through no fault of their own.
Public policy and social justice debates might be more informed if what we know about intelligence, especially with respect to genetics, is part of the conversation. In the past, attempts to do this were met mostly with acrimony, as evidenced by the fierce criticisms of Arthur Jensen (Jensen, 1969; Snyderman & Rothman, 1988), Richard Herrnstein (1973), and Charles Murray (Herrnstein & Murray, 1994; Murray, 1995). After Jensen’s 1969 article, both IQ in the Meritocracy and The Bell Curve raised this prospect in considerable detail. Advances in neuroscience research on intelligence now offer a different starting point for discussion. Given that approaches devoid of neuroscience input have failed for 50 years to minimize the root causes of poverty and the problems that go with it, is it not time to consider another perspective?
Here is the second most provocative sentence in this book: The uncomfortable concept of “treating” neuro-poverty by enhancing intelligence based on neurobiology, in my view, affords an alternative, optimistic concept for positive change as neuroscience research advances. This is in contrast to the view that programs which target only social/cultural influences on intelligence can diminish cognitive gaps and overcome biological/genetic influences. The weight of evidence suggests a neuroscience approach might be even more effective as we learn more about the roots of intelligence. I am not arguing that neurobiology alone is the only approach, but it should not be ignored any longer in favor of SES-only approaches. What works best is an empirical question, although political context cannot be ignored. On the political level, the idea of treating neuro-poverty like it is a neurological disorder is supremely naïve. This might change in the long run if neuroscience research ever leads to ways to enhance intelligence, as I believe it will. For now, epigenetics is one concept that might bridge both neuroscience and social science approaches. Nothing will advance epigenetic research faster than identifying specific genes related to intelligence so that the ways environmental factors influence those genes can be determined. There is common ground to discuss and that includes what we know about the neuroscience of intelligence from the weight of empirical evidence. It is time to bring “intelligence” back from a 45-year exile and into reasonable discussions about education and social policies without acrimony.
It is a good book, and I suggest a full reading of it. It is available as an e-book. The Alt Right is correct about the science, and it is therefore unfortunate that they are nearly the only voices speaking in defense of the science. We need more voices like that of Richard Haier.