The Irish curse could be true, according to the latest findings of a Belfast based professor.
Irish men have smaller penises than their US and European counterparts, new research published in the scientific journal Personality and Individual Differences claims.
The study revealed that the average British man's penis is 5.5 inches when erect, while those of the French were at 5.3, followed by Australians at 5.2, reports the Telegraph.
British men also beat the Australians at 5.2in, Americans 5.1, and Irish 5.
Out of the 113 nations, the Congo came out on top, with an average of 7.1.
At the other end of the table, North and South Korea measure in at 3.8.
Richard Lynn, professor of psychology at Ulster University in Belfast, says his research confirms the previous theories of 'race differences in penis length'.
“For most populations penis length are predictable and confirmed,” he said.
Jelte Wicherts, professor of methodology at Tilburg University in the Netherlands, said the paper should not have been published.
He told the The Sunday Times: “This is a brave paper in a controversial area but the data has no methodology and Lynn’s paper should not have been published."
Average penis sizes by country:
Republic of Congo 7.1
South Africa 6
New Zealand 5.5
South Korea 3.8
North Korea 3.8