This study 's researchers , from the Institute of Child Development of the University of Minnesota , had earlier found the same pattern in children aged three and four .
This study 's researchers , from the Institute of Child Development of the University of Minnesota , had earlier found the same pattern in 3- and 4-year-olds .
" The U.S. will find the killers and they will learn the meaning of American justice , " Bush told the crowd , which burst into applause .