 However, both these arguments have been challenged on empirical and philosophical grounds. While some studies do indeed show that a subset of donor-conceived individuals suffer psychological distress from not knowing the identity of their progenitors, others show that such distress is not common, and is not particularly severe when it does arise (Melo-Martín 2014; Haslanger 2009). Studies also show that early disclosure helps children incorporate the fact that they were donor-conceived into their identity and sense of self, thus helping donor-conceived children avoid some of psychological harms associated with genealogical bewilderment (Golombok et. al. 2002). Advocates of the permissibility of donor anonymity thus argue that there is no clear evidence that donor anonymity is likely to result in severe harm to offspring. If anything, the evidence suggests that we should have a policy of early disclosure.