In a 2005 report commissioned by the National Institute of Justice, researchers examined a variety of sexual assaults and other physical assaults against women. The researchers found that potential rape victims who resisted their attackers physically and verbally significantly reduced the probability that a rape would be completed and did not significantly increase the risk of serious injury. A separate study found that even when a rape was completed, women who used some form of resistance had better mental health outcomes than those who did not resist.
Perhaps just as significant were the findings as to what a victim should not do:
According to the researchers, the only self-protective tactics that appear to increase the risk of injury significantly were those that are ambiguous and not forceful. These included stalling, cooperating and screaming from pain or fear.