As a sort of tribute to the recently deceased Philippe Rushton, let's take a look at the data on presented by Rushton's colleague Richard Lynn in the journal Personality and Individual Differences on average penis size and how that relates to the late professor's embrace of E. O. Wilson's r/K selection theory applied to humans (a framework whose time seems to have come and gone).
Lynn's data collection methods and subsequent transcribing of said data have come in for a fair share of criticism throughout the duration of his academic career, and his data on self-reported penis size--apparently entirely lacking in the way of any controls--aren't devoid of it. But hey, he's working in the inherently incurious and obfuscating environment that is contemporary academia. Don't make the good the enemy of the perfect.
Being the autistic nerdling that I am, I located the full data set rather than just information on the few select countries that showed up in all the write ups about the research when it was announced a month or so ago. Correlating those numbers on average erect male penis size from 119 participating countries with the most recent data on infant mortality rates yields a whopping r-value of .11, p = .23 (that is, the results are not statistically significant).
In other words, there is essentially no relationship between penis size and a population's spot on the r/K continuum, or at least no evidence of such from the data Lynn presents.