it's friday here on "gma." Aerowean going to our new series, "mom confidential." Researchers at rockefeller university say they have found a genetic link that can help determine if some women were... See More
it's friday here on "gma." Aerowean going to our new series, "mom confidential." Researchers at rockefeller university say they have found a genetic link that can help determine if some women were born to be moms. Abc's juju chang is here with more on this controversial new study. Kicking up a little controversial. Do you ever wonder why some women hear their biological clocks so loudly? And others, not so much? Those researchers at rockefeller university says maybe the mo term instinct is just that, it's an instinct linked to a specific gene they've isolated. But are moms hard-wired to be good moms? The study has sparked an intense debate among moms and would-be moms everywhere. Lori is a 3-year-old who hasn't been out of diapers that long. But knows how to change them. Her 5-year-old sister is kindergartner who already knows what she wants to be when she grows up, a mom. Do you know for sure you want to be a mommy? Yes. Reporter: And how many babies do you want? Two. Reporter: Researchers at rockefeller university now says the longing they feel, playing with strollers to feed and nurture baby dolls from such an early age, may be linked to something they're born with. Some are calling it the mommy gene. By studying mice they have determined there's a single gene that could be responsible for motivating mothers, to protect, feed and raise their young. The study's findings means there could be a valid explanation as to why some women, like tv's marge simpson and carol brady -- take your lunch -- Reporter: Seem like natural maternal figures. While others like "man men's" betty draper seem detached and cold. Go bang your head against the wall. Reporter: And some seem like they're not meant to be mothers at all. Like "sex and the city's" samantha. I made my point. And he made his. Reporter: The study's findings make sense. I was always thinking, I'm going to be a mom. I do have friends who say they just -- they don't have it in them to want to have a baby and care for them. orter: ANOTHER MOM ARGUES The maternal instinct may have less to do with genetics than with circumstance. On a good day, I'm incredibly nurturing. On a bad day, it's a little bit harder. Reporter: And mommy gurus told me they worry the gene study may give good moms to beat up on themselves and one another. It could almost invite us to look at someone who does something differently than we do and say, oh, she doesn't want to breast-feed. Maybe she doesn't have the mommy gene. Reporter: And these girls told me, bag mommy may not be for everyone. But for them, it feels right. Joining us, now, to look more closely at the study, is dr. Jennifer ashton, author of "your body beautiful." And parenting coach, tammy gold. Dr. Ashton, what I think is do i have the mommy gene? I already have two kids. So, I might be in trouble. Do you know if you have the mommy gene? Not yet. And this test is not commercially available yet. Women cannot go into their doctor's office and ask to be tested for the gene. But I think one thing that it brought to light with this new study is that this is the quintessential dialogue of nature versus nurture. Just because you don't have the gene doesn't mean you can't compensate for that. And this isn't the full picture of parenting. It's a small slice. But pretty interesting and pretty important. And, tammy, you're a parenting coach. You're sitting there with these women. Do you find that some women find it harder to be moms? And are they searching for an explanation why? They can be just good moms. But sometimes they find it more difficult. Whole isn't there. And it's most evident during times of stress. The moms that feel more maternal, they're less angry because they feel, it's okay. She feels that maternal pull and can get back to her baseline. The moms that don't feel as maternal, have a harder time recovering and seeing the greater point of what's going on. Juju, you were talking to moms. Do they express my fear? What if I don't have the mommy gene? And what does that do to us as women? I don't know a single mom, whether you say I've always wanted to be a mom. There's not a single mom out there that doesn't have ambivalence or get freaked out at the idea of becoming a mom or during motherhood. This gene that it would expose you one way or another is really a shame. What a lot of moms told me, oh, great. Here's another thing to divide us and judge each other. She doesn't have the mom gene. That's why she's acting that way. There's a lot of that going on. And that's what moms are afraid of. Let's bring the men into this, dr. Ashton. Is there a gene out there potentially for men? Whether or not they'd be good fathers? Time will tell. This is the exciting field of molecular genetics. And I'm sure we all know many enthat are more maternal/fraternal than women. It validates those women out there who say, this is not for me. And maybe now, science -- it's recognizing that. Exactly. If you don't have the genes, could you still be a good mom? Yeah. You can compensate. Absolutely. Every mom is so hard on themselves. Just because you don't feel delighted changing a diaper doesn't mean you will not be a good mom. You can compensate for it. Yon be a terrific mother. And moms have to allow themselves not to be excited all the time. To be a mom. And they have to have confidence that they're the best mother they can be to their child. I'll admit. I was someone who grew up thinking, I don't know if I want to be a mom. I wasn't playing with dolls. Yet, when I held my children, i knew I was going to be a mom and a good one. Absolutely. This is another good example of human behavior is not I have the gene, I don't have the gene. Human behavior is on a spectrum in so many different ways. And this is another way of manifesting. It would be a shame for a career woman to use this gene to say, I'm not cut out for this. I think it's more information. And when you take a very complex behavior like mothering or parents and you can put some science and some genetics behind it, it's very interesting. But again, it's a piece of that puzzle. It's such a complex thing when you talk about it. There's so many other things that enter into it. The discussion will go on an own. Ladies, thank you so much. We appreciate your time.
This transcript has been automatically generated and may not be 100% accurate.