Have you ever cheered when a bad guy gets what he deserves in a movie’s closing scene? Or watched a child tattle on a classmate who broke the rules? 
 
 Scientists believe the urge to punish bad guys and reward good ones may be hardwired into the human psyche, and a new study suggests that even infants prefer to see punishment for an unkind act. 
 
 To test this urge for retribution, researchers put on different puppet shows for 100 babies in three age groups: 5 months old, 8 months old and 19 months and older. 
 
 The babies watched puppets behave positively or negatively toward one another – one elephant helped a duck open a box, while another elephant slammed the lid shut. Next, the children saw the “good” or “bad” puppets get rewarded or punished – a toy moose either gave a toy to the elephants or took the toy away. 
 
 When the babies were prompted to choose their favorite puppets, the researchers reported that most of the 8-month-olds preferred the puppets that had punished the “bad” puppets, while the majority of the 5-month-olds preferred the moose that treated everyone kindly, even the “bad” elephants. The children 19 months and older acted similarly to the 8-month-olds, physically taking treats away from puppets who had mistreated others. 
 
 The study was published this week in the Proceedings of the National Academy of Sciences. 
 
 Study author Kiley Hamlin, a psychologist from the University of British Columbia, said the results offered some clues about exactly when humans develop a sense of justice, a factor that evolutionary psychologists say is critical to the function of society. 
 
 “Somehow between age 5 and 8 months, the babies get this much more nuanced perception, the ability to interpret circumstances,” Hamlin said. “It’s hard to argue that parents are teaching their children to punish at 8 months. It’s a very complex idea. If they are learning it, they’re doing it on their own, suggesting that there is some kind of system for learning it.” 
 
 Rahil Briggs, a child psychologist and director of the Healthy Steps program at Montefiore Medical Center in the Bronx, N.Y., said scientists knew very little about what happened in a baby’s brain in the earliest months of life. But she said that other complicated concepts started to become apparent to infants, such as a sense of self and the characteristics and motivations of others, at around 6 months old. 
 
 “There’s all sorts of things that we think start to emerge around that age that all point to the fact that babies become more aware of distinctions,” Briggs said. “I think as we continue to do this research that people are going to continue to be surprised and impressed by how sophisticated babies really are.” ||||| Turns out everyone does have a price — even babies. 
 
 Babies as young as 12 months will take a smaller offering from a Good Samaritan than a larger one from a wrongdoer. However, children are much more willing to “do business” with the bad guy when their offer is substantially higher than the do-gooder’s, a new study published in the journal Cognition shows. 
 
 “It’s a study I like to call ‘the deal with the devil’” said Arber Tasimi, a graduate student in the Department of Psychology who led this study along with Yale psychologist Karen Wynn. 
 
 The experiment that Tasimi and Wynn designed was simple: When given the choice between a smaller and a larger offering, which do children and babies choose? Unsurprisingly, they almost always take the larger amount. But the researchers wanted to know if it matters who was doing the offering — a good guy or a bad guy. 
 
 In one experiment, 5- and 8-year-olds were introduced to two characters, one described as mean and the other described as nice. Children were then told that the mean kid was offering them more stickers (either 2, 4, 8, or 16) than the nice kid, who offered a single sticker. When the difference between the offerings was modest, most children were willing to reject the larger number of stickers and deal the nice kid. But, when the offer was upped to 16 stickers, most children were willing to “sell out’’ to the mean kid. 
 
 Even 12- and 13-month-olds seem to struggle with this moral dilemma. Tasimi and Wynn showed babies a puppet show involving a puppet attempting, but failing, to open a clear box with a toy inside. On alternating trials, one puppet helped open the box, whereas another slammed it shut. Afterwards, the mean puppet offered two crackers and the nice puppet offered just one cracker. Remarkably, said the researchers, over 80% of babies took the single cracker from the nice puppet. But when the mean puppet’s offer went up to eight crackers, babies showed a greater willingness to deal with a wrongdoer. 
 
 “When I tell people about these findings, they often joke that babies and kids are sellouts, but I think the message is less cynical,” Tasimi said. “Even early on, we’re willing to pay personal costs to avoid wrongdoers in favor of do-gooders.” 
 
 And, what about those participants who reject any amount from bad guys? 
 
 “I think an exciting avenue for future research involves an understanding of how individual differences, even during the first few months of life, influence our judgments of good and bad, right and wrong,” he said. 
 
 (Photo courtesy of Shutterstock)
– Even at eight months old, we seem to have a desire to see evildoers punished. Researchers showed groups of babies a puppet routine in which one elephant puppet treated a duck puppet well, while another was mean to his puppet peer. In a later scene, a moose puppet rewarded the elephant for his behavior with a toy, or punished him by taking a toy away. The infants then chose their favorite moose. The five-month-olds showed a preference for the moose who had been nice to everyone—even the elephants who’d behaved badly. But most babies eight months old and older liked the moose who punished the mean elephants, ABC News reports. “It’s hard to argue that parents are teaching their children to punish at eight months. It’s a very complex idea. If they are learning it, they’re doing it on their own, suggesting that there is some kind of system for learning it,” said a researcher. Click to watch videos of the puppet situations.