The prevalence of marital rape is difficult to assess, especially outside the Western World. Discussing sexual matters in many cultures is taboo. One problem with studies on marital rape is that the Western concept of consent is not understood in many parts of the world. Because many societies operate on social norms which create a dual system of sexual morality—one for sexual intercourse that is "marital" which is seen as an obligation that cannot be refused, and "extra-marital", which is seen as wrong (or illicit/illegal). Issues of consent are poorly understood, especially by young wives (which are often young girls who do not have a proper understanding of sexual rights). For instance in an interview in a study for the World Health Organization, a woman from Bangladesh who described being hit by her husband and forced to have sex said that: ""I thought this is only natural. This is the way a husband behaves"." Research has, nevertheless, associated specific regions with a very high level of violence, including sexual violence, against women by husbands/partners. An example of such a place is Ethiopia.