It has been theorized that there is a specific gene, which has input into the development of bones, also plays a role in the development of the penis. Is there a correlation between shoe size and penis size? ThundersPlace has a poll that indicateds a weak connection, but it only has under 200 polled. Sizesurvey also shows a weak correlation with shoe size.
While we're on the general subject, ThundersPlace also has a height vs penis poll with around 1300 polled. It doesn't indicate strong, but it doesn't indicate weak either - it's a moderate correlation. The correlation isn't so evident in the overall averages, as the average is only a 1/4" longer penis length for tall guys than it is for short guys, with average height guys having about 1/8" longer penises than short guys, and average height guys having about 1/8" shorter penises than tall guys. The difference becomes the most evident in the outliner penises (longer and shorter penis lengths). Tall guys have a higher occurance of longer than average length penises, and a lower occurance of less than average length penises. The inverse occurs for short guys. Average height guys falling inbetween those ratios. It's enough to rate the correlation as being of moderate strength. Sizesurvey shows a somewhat stronger correlation between height and penis length than ThundersPlace does, but isn't considered as reliable as ThundersPlace is.
The correlation of height to girth is on the mild side, even though it was found that penis length is strongly correlated with penis girth (longer penises tend to have more girth more often). So with height moderately correlated to penis length, and penis length strongly correlated to girth, but yet height only mildly correlated with girth, that indicates height isn't directly correlated with girth. That the mild correlation found between height and girth is an indirect correlation created as the result of girth being correlated to penis length and penis length being correlated to height at higher strength levels.
That's perhaps a bit confusing to read. I'll sum it up.
height vs penis length = moderate correlation
penis length vs penis girth = strong correlation
height vs penis girth = mild correlation (appears to not be a direct correlation, but merely an indirect side effect from the above two correlations)
shoe size vs penis length = weak correlation (less than mild)