Less parental warmth and more harshness in the home environment affect how aggressive children become and whether they lack empathy and a moral compass, a set of characteristics known as callous-unemotional (CU) traits. In a study of 227 identical twin pairs, the research team analysed small differences in the parenting that each twin experienced to determine whether these differences predicted the likelihood of antisocial behaviours emerging. They learned that the twin who experienced stricter or harsher treatment and less emotional warmth from parents had a greater chance of showing aggression and CU traits. The work builds on a growing body of work to assess a variety of aspects of parenting. The findings have been published in the Journal of the American Academy of Child and Adolescent Psychiatry .
