It is one of life 's biggest questions : Are we born knowing the difference between good and evil ? Or are we taught our moral beliefs by parents and society ? Philosophers and psychologists have long believed that babies are born `` blank slates , '' and that it is the role of parents and society to teach babies the difference between right and wrong ; good and bad ; mean and nice . But a growing number of researchers now believe differently . They believe babies are in fact born with an innate sense of morality , and while parents and society can help develop a belief system in babies , they do n't create one . A team of researchers at Yale University 's Infant Cognition Center , known as The Baby Lab , showed us just how they came to that conclusion . Dr. Karen Wynn runs the Baby Lab , and she and her team have been studying the minds and behaviors of babies for decades . About eight years ago they began running a series of studies on babies under 24 months to see how much these babies understand about good and bad behavior . The first test is the simplest . Show a baby an example of good behavior , and then an example of bad behavior , then let the baby decide what she likes . Opinion : Do babies know right from wrong ? They begin with a puppet show . In this show , a gray cat is seen trying to open a big plastic box . The cat tries repeatedly , but he just ca n't open the lid all the way . A bunny in a green T-shirt comes along and helps open the box . Then the scenario is repeated , but this time a bunny in an orange T-shirt comes along and slams the box shut before running away . The green bunny is nice and helpful . The orange bunny is mean and unhelpful . The baby is then presented with the two bunnies from the show . A staff member who does n't know which bunny was mean and which bunny was nice will offer both bunnies at the same time to the baby . The baby 's mother , who is usually present during the study , closes her eyes so as not to influence the baby in any way . Which bunny do the babies choose ? More than 80 % of the babies in the study showed their preference for the good bunny , either by reaching for the good bunny or staring at it . And with 3-month-olds , that number goes higher , to 87 % . So what does this tell us ? Paul Bloom , author of `` Just Babies : The Origins of Good and Evil '' and a professor of psychology at Yale , says these studies show that even before babies can speak or walk , they judge good and bad in the actions of others because they are born with a rudimentary sense of justice . But Bloom , who is married to Wynn , says this sense of justice is `` tragically limited . '' Although babies are born with an innate sense of morality , they are also born with flaws . What 's your baby really thinking ? He writes : `` We are by nature indifferent , even hostile to strangers ; we are prone towards parochialism and bigotry . Some of our instinctive emotional responses , most notably disgust , spur us to do terrible things , including acts of genocide . '' And the role of parents and society is to overcome these limitations and further develop the innate moral beliefs that already exist in those baby minds . Skeptics of the studies say babies are not capable of making intelligent choices , and perhaps babies are drawn to a certain color , or they choose according to where the puppets are placed . The team at the Baby Lab has been very careful in their studies to change the puppets , shirt colors and placement of the animals before presenting them to various babies , and they feel confident their published research is sound . The Baby Lab has developed a series of studies based on the simple premise that babies have this simple understanding of good and bad . The other studies explore reward and punishment , compromise and the roots of bias .
Yale University researchers say babies are born with knowledge of right and wrong . They also have a sense that they can do something to help others, but not necessarily in the way you would think. But bad comes with the good , and parents must guide children , one scientist writes .