In addition 25% of those diagnosed with BPD have no known history of childhood neglect or abuse and individuals are six times as likely to develop BPD if they have a relative who was so diagnosed compared to those who do not. One conclusion is that there is a genetic predisposition to BPD unrelated to trauma. Researchers conducting a longitudinal investigation of identical twins found that "genetic factors play a major role in individual differences of borderline personality disorder features in Western society." A 2014 study published in European Journal of Psychotraumatology was able to compare and contrast C-PTSD, PTSD, Borderline Personality Disorder and found that it could distinguish between individual cases of each and when it was co-morbid, arguing for a case of separate diagnoses for each. BPD may be confused with C-PTSD by some without proper knowledge of the two conditions because those with BPD also tend to suffer from PTSD or to have some history of trauma.