This monograph discusses a recently documented finding which suggests that children in about the 6 to 11 year old bracket may be more vulnerable to crises in their environment than either younger children or older adults. A prerequisite for remedial policies is a sound theoretical understanding of the problem; although this understanding is seen to be nonexistent presently, hypotheses said to be both reasonable and promising are indicated. But, before these or other theoretical explanations are investigated, there is a task that is given priority over all others. This task consists in the documentation of replications that have been carried out. The original Israeli study and a Canadian replication are discussed in the introduction and in a chapter consisting of additional evidence for the phenomenon. Another chapter analyzes and reports for the first time the Talent Data bank. This progress report on the evidence which has been assembled in support of the existence of a vulnerable age effect suggests that the effect in mid-childhood is clearly and recurrently observable for boys. For girls too, the effect is noticeable, although not invariably so. A school selection effect is distinguishable as well; however, its impact on migrants is somewhat less predictable for boys, and even less so for girls, than is the vulnerable age phenomenon proper. Areas for needed future research are indicated. (Author/AM)