To James McKenna, it’s a matter of human biology.

To the American Academy of Pediatrics (AAP), it’s all about safety.

The difference of opinion centers on the recommendations released this week by the pediatricians organization on where and how infants should sleep.

The AAP says babies up to 1 year of age should sleep in the same room as their parents.

They say this arrangement can reduce the risk of Sudden Infant Death Syndrome (SIDS) by as much as 50 percent.

However, the AAP recommends against babies under 1 year of age sleeping in the same bed as their parents.

They say this can result in accidental suffocation and other serious problems.

"We want to share this information in a way that doesn't scare parents but helps to explain the real risks posed by an unsafe sleep environment," Dr. Rachel Moon, a professor of general pediatrics at the University of Virginia Health System, and lead author of the AAP report, said in a press release.

McKenna, a professor of anthropology and director of the Mother-Baby Behavioral Sleep Lab at the University of Notre Dame, agrees with the AAP’s recommendation on same-room sleeping.

However, he sees the recommendation against using the same bed as something that is counter to 3.5 million years of human history.

Read more: Back sleeping credited with reducing SIDS deaths in infants »

Beds for babies

McKenna says human babies are some of the most dependent creatures on Earth.

They have an extraordinary need for contact. That includes feeling the “presence” of a caregiver, in particular a mother. That can include a mother’s smell, her breath, and her body heat.

“Human babies are born extremely dependent on these external stimuli,” McKenna told Healthline. “Babies are contact seekers.”

McKenna said this is particularly true when a mother is breast-feeding, something the AAP does strongly recommend.

Having a baby breast-feed and then moving them back to a separate bed isn’t natural.

“It puts mothers in an untenable position,” he said.

McKenna notes that infants have slept next to their parents for millions of years and continue to do so in cultures outside the United States, in particular where one-room housing is common.

He acknowledges that sleeping arrangements have changed over human history with the introduction of beds, blankets, and temperature-controlled homes.

But McKenna said the basic biological need is still there.

Babies need to be close to their caregivers when they are sleeping.

McKenna extends his arguments to naps.

He says it isn’t necessary to put a baby down in a bed or separate room. Placing them in a bassinet or stroller near a parent is fine.

He also dismisses the notion that babies should be on strict sleep schedules. Waking up in the night or taking a shorter nap than planned is natural.

“Babies will sleep when they need to sleep,” McKenna said.

The Notre Dame professor believes today’s infant sleep patterns are a development of modern society that goes against nature.

He says the notion of individualism and autonomy have fed into this phenomenon as has the notion of not “spoiling” a child.

The emergence of the household where both parents work is another contributing factor. Baby schedules sometimes have as much to do with parents needing sleep.

“I think exhausted parents are open to hearing these recommendations,” McKenna said.

Read more: Baby hospitals may not be that healthy for infants »

Same room is enough

This week’s AAP recommendation is an update from their 2011 policy announcement.

The emphasis is on safety.

AAP officials note that 3,500 infants die every year in the United States from sleep-related deaths. The causes include SIDS, accidental suffocation, and strangling.

The organization states that having babies sleep in the same room as parents can reduce this risk by 50 percent.

“Parents in the same room have more opportunities to respond to a baby’s needs,” Dr. Lori Feldman-Winter, the division head of Adolescent Medicine at Cooper University Hospital, and a co-author of the report, told Healthline.

Feldman-Winter said when babies sleep in separate rooms they tend to sleep longer and deeper. That, she said, isn’t necessarily healthy and may be a contributor to SIDS.

The AAP recommends that the baby’s bed should be bare without crib bumpers, soft toys, blankets, or pillows.

The baby should be placed on his or her back in a bed equipped with a tight-fitting sheet.

The AAP, however, insists that the sleeping surface be separate from the parent’s accommodations.

Feldman-Winter said babies in the same bed can be accidentally suffocated by a blanket, pillow, or even loose sheet.

This is particularly true for premature babies or babies under 4 months of age.

Feldman-Winter said there are some alternatives for mothers who are breast-feeding. Among them are bedside sleepers that are adjacent to the parents’ bed.

She agrees with McKenna that modern society has changed the rules on infant sleeping situations.

Parents who work and a lack of long-term paid maternity leave are among the issues.

“There are a lot of stresses that factor in,” she said.