Given the finger, Dr. Hurd says he finds the evidence compelling. A March 2, 2005 press release (from the University of Alberta) makes this plain:
Dr. Peter Hurd initially thought the idea was “a pile of hooey,” but he changed his mind when he saw the data.
Hurd and graduate student Allison Bailey have shown that a man’s index finger length relative to ring finger length can predict how inclined that man is to be physically aggressive. Women do not show a similar effect….
(Thanks to investigators Tom Roberts and Thomas J. Roberts for pointing this out to us.)