From photos of mom's like Victoria Beckham -- kissing their kids on the lips -- to Kristin Cavallari posting pictures of her sons at the beach -- to Chrissy Teigen going on a date with her husband shortly after giving birth.

Everybody has an opinion. When you become a parent, that becomes abundantly clear. Those celebrity photos --all started a string of criticism we have now come to call mommy shaming.

So why do we do it? So why do we feel it necessary to weigh in on what other people do?

We had a conversation with four moms, one of whom is a psychologist, about why women are so hard on each other.

Michelle Cummings, mother of two teens: “That's a tough one. Nature? I mean women, I hate to say it, nature, a little cadiness. I don't know. I don't know the answer to that."

Psychologist Dr. Hillary Cauthen: “Why are women so hard on themselves or judging others I think that's the bigger question right? Naturally I think we judge people as a society when we look at society we're really harsh on moms compared to dad.”

Cummings: “I think maybe one part of it is we don't respect motherhood as much as we should and that's generations back. The woman being home raising the children, it's a very important job, but not everybody has that luxury or as many opportunities back in the day. I think that's some insecurity maybe. Women, unfortunately, not accepting the fact that what you do is very important.”

Natalie Penland, mother of three, an 11, 12 and 15 year old: “Probably what would take away a lot of the issues of judging other parents or parents judging you is to recognizing we all do things a little bit differently. And this may be an area that I'm so called lacking, but you're great at it so let's partner up. Encourage each other and our strengths. A Pinterest buddy support for you untalented people.”

Cummings: “I think it's self-imposed sometimes.”

Dr. Cauthen: “I think we criticize moms generally others mothers, parenting is now another sport, this competitive nature of who's doing it the best. And unfortunately it's our own self doubt that we have. The validation that we're not seeking. So if you see a mom doing something that we can criticize, it's probably because we're not getting that validation ourselves and not being supported and not being told, ‘Hey you're doing a good job.’”

Lindsay Meredith is a mother of a two year old, with another on the way: “Pressure. I feel a tremendous amount of pressure. Am I doing this right? Especially, it's my first child, so I don't know what I'm doing, as much as I wish I did. I put so much pressure on myself that I think maybe more people are judging me than really are.”

Dr. Cauthen: “Best thing we can do for each other, any time you're a parent, whether it's biological or by choice, there's no set way you can read all the books. You can't control it. And you're raising this part of you to become something better right? You are putting a part of you out in the world and so you're really vulnerable you are putting this child out to represent me and my family and my beliefs. We don't know how to do it and if we can't control it we get nervous.”

Penland: “Good luck and be kind to each other. Be kind. Lead by example, it's the Christian thing, lead by example.”

Cummings: “Be a support when you see someone who needs it. Don't be too hard on yourself. I think that's my biggest struggle as a parent. I can create that pressure for myself. So give yourself a break you're doing the best you can.”