Is it the ‘terrible twos’ or the beginnings of anti-social behavior?


Toddlers are not the nicest people. If, like me, you’ve got one at home, you’ve been on the receiving end of hitting, screaming, and flying chunks of macaroni and cheese.

But when is a child’s bad behavior just the “terrible twos” and when it is something more? A new nationwide study of 561 adopted children and their families has revealed a set of behaviors that identify which children are at risk for severe antisocial behavior later in life. These behaviors are strongly inherited through our genes, the study found, but they can be offset by positive parent-child interactions.

“Biology is not destiny,” says co-author Luke Hyde, a psychologist at the University of Michigan. “Even kids that seem difficult early on can definitely change.”


Antisocial behaviors, such as lying, cheating, and aggression, put children and teenagers at risk for getting into trouble with the law and being incarcerated. In order to intervene as early as possible, psychologists have long wanted to know how and when such behaviors first emerge.

Get The Weekender in your inbox:
The Globe's top picks for what to see and do each weekend, in Boston and beyond.
Thank you for signing up! Sign up for more newsletters here

Hyde’s group and others recently identified a set of “callous-unemotional” behaviors that show up in children as young as age 2 and signal risk for later behavioral problems. These include lack of empathy, little emotion, and lying.

But where do such behaviors come from, and can they be prevented? To answer those questions, Hyde and colleagues analyzed data from the Early Growth and Development Study, a national study of birth parents and adoptive families. Shortly after the adoption, the biological mothers took a survey, which Hyde’s team used to assess their antisocial behaviors.

Next, the team observed videotaped play sessions of the adoptive mothers and children at 18 months old. Finally, each child’s behavior was assessed at 27 months of age. That is about as young as a child can be to accurately measure if he or she is showing callous-unemotional behaviors, says Hyde.

The team found that if a biological mother had strong antisocial behaviors — despite no contact with her offspring — her child was likely to exhibit callous-unemotional behaviors. “These behaviors are very genetic,” says Hyde.


But when an adoptive mother regularly gave positive reinforcement to her son or daughter — such as “good job” or “thanks for picking that up” — the chances of that child showing callous-unemotional behaviors at 27 months went way down, even if the child was at high risk. So a mother or father can essentially wipe out the risk that a child will develop antisocial behaviors through positive parenting.

And it’s not just adoptive parents who can make a difference for their kids, emphasizes Hyde. Even parents with known behavioral problems can take advantage of proven, effective interventions to decrease behavioral problems in their children. “You can go see a psychologist who specializes in early childhood,” he says. “Even kids who are at the greatest risk are not destined for bad outcomes.”