When parents act warmly and responsively toward young children who exhibit antisocial behavior, the children begin acting more warmly too.

That’s according to a new study in the Journal of Clinical Child and Adolescent Psychology, in which researchers examined whether there are differences in response to parental harshness and warmth among three-year-olds who exhibit “callously unemotional” behavior.

These findings "highlight the toddler years as a key intervention period to reduce the likelihood that children with callously unemotional behavior will develop more entrenched and severe conduct problems."

To parents of little ones, this outcome might seem obvious, but the study’s results contradicted the prevailing thinking on the matter. Until now, it has been widely believed that children whose behavior problems include high levels of “callous-unemotional” behavior, characterized by a “lack of empathic concern, punishment insensitivity, and lack of emotional responsivity,” are that way regardless of parenting style. Now, however, there’s evidence that colder parenting may worsen this type of behavior, while warmer parenting might coax out a child’s empathy.

The researchers, led by University of Michigan psychology post-doc Rebecca Waller, defined “warm” parenting as that which is responsive, positive, and affirming. Children whose primary caregivers are warm, they found, are much less likely to be insensitive to others, implying that we can reduce toddlers’ misbehavior just by being kinder to them.

Early behavior problems can evolve into lifelong issues with aggression and isolation, the researchers note. And it's more difficult to change the “callously unemotional” behavior of older children because they are already desensitized to punishments. These findings, then, “highlight the toddler years as a key intervention period to reduce the likelihood that children with CU behavior will develop more entrenched and severe conduct problems.”

Similar studies have been conducted, but they've been demographically limited with a focus on a wider age range with mostly male subjects. This one, by contrast, used a multi-ethnic sample group of about 350 children ages two to four, half of which were female. They chose subjects at risk for “callously unemotional” behavior by looking at how the children behaved, how their primary caregiver acted, and demographic factors.

Every year from age two to four, the researchers checked in on the parent-child pairs at home. To assess whether a toddler’s behavior was improving, the researchers relied on parent reports. They coded parental warmth and harshness, in turn, by observing parent-child interactions, including five-minute speech samples.

In a follow-up paper, the researchers found that a parent’s level of warmth and a child’s callous behavior are reciprocally related, according to University of Michigan psychologist Luke Hyde. “Specifically, if children had high callous-unemotional behavior at age 2, this was related to a decrease in parental warmth at age 3," Hyde, who worked on both studies, explains in an email. "Likewise, if parents showed low levels of warmth at age 2, children’s levels of callous unemotional behavior had increased by age 3.... This is important because it shows that it is more difficult to parent some children but also that parenting can have an effect on these early severe behaviors.”

“Parental harshness seems to be bad for all children,” Hyde says, “but parental warmth may be particularly important for kids with these risky callous-unemotional traits.”

Rosie Spinks contributed reporting.