Good summaries of this study can be read in a report by Catherine Griffin called "Pet Chimpanzees Suffer Behavioral Problems for Years After Human Contact" in which Dr. Ross notes, "One of the startling aspects of these findings is that these behavioral effects are so long-lasting," and in a news release titled "Chimpanzees raised as pets or performers suffer long-term effects on their behavior" in which he states, "Denying them [chimpanzees] access to members of their own species, during the critical infanthood period, results in behavioral outcomes that last a lifetime. Even with the best possible care as adults, they often can't fit in with the other chimpanzees."
There are a number of important aspects of this study. First, it is clear that early experience significantly influences later behavior and individuals reared in captivity will need a good deal of special attention in attempts to override the consequences of abnormal rearing and the behavioral deficits from which they suffer. Second, there is significant individual variation in responses to captive rearing in terms of social and sexual behavior, and the authors correctly stress that "Future studies should help identify what variables lead to better social resilience in order to aid chimpanzees who struggle more with social integration." In addition, because it is virtually impossible to place these individuals back in the wild, they will have to live their lives out in a variety of captive conditions and knowing that they lack normal behavior will help in developing management strategies based on individual behavioral profiles and personalities to meet their social needs.