 However, some factors have significant causal evidence supporting them.American clinical psychologist David Lisak, co-author of a 2002 study of undetected rapists, says that compared with non-rapists, both undetected and convicted rapists are measurably more angry at women and more motivated by a desire to dominate and control them, are more impulsive, disinhibited, anti-social, hypermasculine, and less empathic.Sexual aggression is often considered a masculine identity characteristic of manhood in some male groups and is significantly correlated to the desire to be held higher in esteem among male peers.