Some parents across the United States are deliberately keeping their child's sex hidden and are instead raising so-called "theybies."

The idea behind a "theyby" -- as opposed to a "baby" -- is that only the child itself should be able to decide its gender.

Cathy Areu, publisher of Catalina Magazine said Friday on "Tucker Carlson Tonight" that she supports the rise of theybies.

"It's about allowing the baby to decide what gender that baby wants to be when that baby can decide, which is around four years old," she said.

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Carlson asked Areu why parents would hold information back from their children about what makes males and females different.

"Why would you not tell your kids about that?" he asked.

Areu argued that around the age of four is when children are aware of the differences so before that age, parents should not label them.

"Around zero to four, we're not going to say to a little girl that 'You're a little princess' or to a boy, 'You're such a tiger.'"

Carlson then asked if we should ignore definitive aspects of society like temperature, traffic and weather if parents are going to deny their child's gender at an early age.

"We acknowledge biology and nature as real, right?" he asked.

Areu answered by asking who should care about defining genitalia, as parents are still bringing a human into the world regardless.

"Because men and women are completely different in key ways," Carlson said in response. "Can you not say that anymore?"

Watch the segment from "Tucker Carlson Tonight" above.

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