Researchers tested their hypothesis in the 42 U.S. presidents up to and including George W. Bush using (a) psychopathy trait estimates derived from personality data completed by historical experts on each president, (b) independent historical surveys of presidential leadership, and (c) largely or entirely objective indicators of presidential performance.
"The same thread of rhetoric is also coming from the U.S. and Britain whose hypothesis is that any victory by a ruling party in Africa (means) the elections are not free and fair, " he said.