Yale developmental psychologist Paul Bloom has written several books about pleasure, morality and infant psychology. His most recent, “Just Babies: The Origins of Good and Evil,” discusses his new research on infant morality and the innate sense of right and wrong that appears early in childhood. The News talked with Bloom about his new book, his research partnership with his wife and the impact of his work on our philosophical understanding of instinctive morality.

Q Where did the inspiration come from to write Just Babies?

A Well there are two main sources. One is the research that I have done with my colleague and wife Karen Wynn, which is what we did with morality and babies in the [Yale] cognition center. We made some really striking discoveries about babies’ early knowledge, and I was just dying to talk about them and to tell the story of our research. The second reason, more generally, was that I have always been interested in morality. A lot of my research performed with children and with adults concerns the nature of overall existence. The motivation for writing the book was to give a broad theory about moral ways, looking at how we began and what we end up as, looking at what is universal and what is different.

Q Did your research begin with your interest in childhood behaviors and lead to researching morality, or vice versa?

A I have always been interested in morality, and for many years I’ve been doing research with adults, looking at the nature of moral judgments, looking at the nature of political differences in liberals and conservatives, the role of disgust and of sexual arousal, and our moral feelings. But at the same time I have also been doing research with babies, looking at their social understanding and their judgments of other people. So one way of looking at it is that the two interests came together in this book.

Q In your book you argue that babies have an innate sense of morality. How does one go about testing this in a research setting?

A If I want to know what your morals are like I can just ask you, but it is different with babies. There are different ways of studying babies, but what we did was construct one-act plays, with a main character struggling to get up a hill. A second character would help gently nudge him upwards, and a third would push him downwards. Then we showed the baby the two other characters, and you can see which ones the babies prefer [by] the one they reach for. When they get older you can see which one they want to reward and who they want to punish. You can see what they think about other characters who punish the bad guy or reward the bad guy. The main result we get from all of these studies is that the babies have a moral sense and are able to judge right from wrong.

Q Since there seems to be a right and wrong answer in this situation, or a correct choice in character to reach for, does this lead to conclusions that some babies are morally “bad” and others morally “good”?

A We often get questions about the children who don’t choose good characters. Some babies don’t give us the results we are looking for, but our results do tend to be very strong in these studies: The vast majority of kids behave morally. I do think though we are born with differences in empathy, certain differences in compassion, but this research suggests the capacity to judge right from wrong — the basic moral understanding — is universal.

Q There are many different perspectives on the innate morality of babies. Do you find that your research supports the theories of any one movement?

A The findings from the baby lab support a nativist conception of human psychology, where fundamental capacities are inborn. But at the same time, I should emphasize that the innate morality we have is incomplete. It is tragically limited in certain ways. This leaves a lot of room for learning and for development. You and I believe that sexism is wrong, we believe that slavery is wrong and that every human being has rights. All of these beliefs are the product of development. So a substantial amount of our moral understanding is learned later, but a lot isn’t. A lot of my book focuses on the story of how we come from being just babies to being fully moral beings.

Q How did you get started as a developmental psychologist? Did you always want to work with children?

A My wife and I have two teenagers, and when they were younger we did experiments on them, but I don’t think they were harmed by having developmental psychologists as parents, nor do I think we had any special insights to help them.

Q What is it like to be married to and work with one of the most famous developmental psychologists today?

A I love it. I love the fact that I am married to someone who is a brilliant scientist and a terrific writer. I don’t know what it would be like to live my life in a different way. That said, it has its pluses and minuses, but the arrangement we have where we do some of our work together has been wonderful. When we are home together at night we do what most people do which is gossip, but we also talk shop and talk about our research.