As we explained earlier, some authors have deduced that the impact of parental warmth is likely to serve as a protector against the adverse effects of other risks. For loved children, the impact of peers, community, school problems, biology and the like may be attenuated, even if warmth in and of itself exerts a small direct effect on offending. There are quite a few studies that look at this issue, but most use general conduct outcomes.
In studies about violence, we found a few that looked at interactions between parental warmth and criminogenic factors. Brendgen et al. (2001) tested whether mothers’ or fathers’ warmth and care moderated the association between early proactive or reactive aggression and later violent behavior in a teenage sample. They wondered whether parental warmth could prevent the continuity of aggression over time. Among several interactions tested for two outcomes (delinquency- related violence, dating violence), they found one significant interaction. Maternal warmth moderated the association between reactive aggression and later dating violence such that reactive aggression measured at age 13 had a stronger influence on dating violence at ages 16-17 when mother’s warmth was low; in fact, the relationship between reactive aggression and later dating violence was no longer significant for those whose mothers had warmth scores more than 1 standard deviation above the mean. Unfortunately, all the interactions were in the model simultaneously, which makes the set of findings difficult to interpret. Stacks et al. (2009) tested but did not find that warmth moderated the effect of spanking on aggressive behavior. They tested this in 3 different ethnic groups.
With regard to interactions between rejection and other risks influencing violence, the most prominent of these were published by Raine and colleagues (1994, 1997) using large Northern European samples. Raine, Brennan, and Mednick (1994) report only an interaction effect between maternal rejection and birth complications (so their study is not included in our tables). They found that among participants in a male cohort in Copenhagen, those who had experienced early maternal rejection and birth complications had a highly elevated chance of violent offending later in life. Replicating their earlier study assessing violence using adult data up to age 34, Raine and colleagues found that early maternal rejection combined with birth complications predicted violent but not nonviolent offending (Raine, Brennan, & Mednick, 1997). The interaction remained significant even when they controlled for the total number of crimes committed (chronicity). The interaction was also significant when predicting serious violence, and no main effect of birth complications or early rejection remained once the interaction was added to the model. This is a compelling and widely-cited study. However, Brennan et al. (1989), also using the Copenhagen data, reported numerous interaction tests between maternal rejection and biological factors such as maternal smoking, and none of them produced a statistically significant coefficient.
Thus, broad conclusions about “warmth” as a protective factor must be delayed; the evidence is simply not extensive enough to make a firm statement on this point. Our conclusion about parental rejection, however, is that it appears to exacerbate the effects of numerous risks.