Humans overlap in appearance quite a bit. This might surprise you, and you might not believe me. But I think to some extent this perception is a quirk of human psychology, we tend to shoehorn individuals into racial types which we conceive of as very distinct, perhaps more distinct than they truly are.
The fact is that human normal variation is subject to some constraints in terms of function and extant genetic variation. To the left are photographs of the Icelandic singer Bjork and a Bushman woman. Contrary to rumor Bjork is not half-Chinese or part Inuit. No doubt her ancestry is a mixture of Irish and Norse homogenized through centuries of local breeding and population bottlenecks. Nevertheless, her physical appearance suggests to people that she of Asian provenance, and she has noted that she was mocked for being Chinese as a small child, suggesting that she is an extreme end of the Icelandic range. The point though is that some northern Europeans have a vague Asian cast to their features, and this does not necessarily have to do with some distant ancestry from the eastern regions of Eurasia, rather, it is simply part of the normal range of variation.
In contrast to Bjork the Bushman woman is of normal type for her group. Though African one might accept that she has an Asian cast to her features, and in fact when Bushmen in Botswana met Vietnamese workers they assumed that they were of the same race (as opposed to the Bantu speaking African agriculturalists and herders who were their neighbors). We know from analysis of neutral markers that there is no close genetic relationship between Bushmen and East Asians, rather, there are only so many ways to chop up human genetic variation to produce a modal type, and so some forms reoccur. These are extreme cases, but I think it is important to keep in mind that there is overlap in the finite suite of characters which contribute to our perception of someone's racial identity, and that may be the source of the tendency of many children to favor once side (there is also the reality that many Eurasian children, for example, are assumed to look Asian by Europeans and look European by Asians).
Mixed-race but homogeneous appearance? : Gene Expression