I found this in an article on military families in relation to child abuse statistics, but it sounded equally applicable to some missionary families - not in the category of abuse but in another area:
Geographic Mobility and Isolation
The frequency of moves has a significant effect on the family and the personality of its members. They may develop a sense of restless transiency and superficial relationships with a tendency to avoid deeply felt extrafamilial attachments to lessen the hurt of separation. Furthermore, frequent moves disrupt ties to the extended family structure. This requires increased dependency on the nuclear family which itself is often confronted with periodic splitting because of temporary assignments and isolated tours of the father. Sorokin (1959) noted a definite relationship between pathology, alienation, and geographic mobility. Other studies (Gabower,l960; Hi11,1958; Pedersen and Sullivan,1964) also imply a detrimental effect of mobility. [Emphasis added].
Hm. Y'think this might shed any light on someone's fear of intimacy or commitment?
Of course, since this was just a study, there were no helpful tips on how to overcome any negative effects of the geographic mobility and/or isolation, but this is just a point along the path.