Babies Are Innately Fearful of Plants, Says New Research

A baby's hand touching plants outdoors.

Rungnapa Tarasiri / EyeEm / Getty Images

Does your baby seem to put everything in its mouth except for the houseplants? Well, there might be a reason for that. New research suggests that babies may actually have an innate aversion to plants, reports Discovery News.

The discovery wouldn't be the first time that babies were found to be born with an innate fear, but most of the time such fears are directed toward dangerous animals, such as snakes. This would be the first time an inborn apprehension has been discovered directed at plants.

It may seem strange that babies should be scared of plants, since they are inanimate, but poisonous plants are actually much more widespread than poisonous critters. It's therefore not surprising that such an aversion should have evolved.

"In most modern lives, plants are mostly part of the background and sort of an afterthought," explained Annie Wertz, one of the study's researchers. "But when you think of humans in their historically natural environment, plants were a huge part of their lives."

Given that plants are ubiquitous in the surrounding environment, it's remarkable that poisonous vegetation is not a more common hazard for babies than it is. This is especially true if you factor in the propensity of babies to put objects in their mouths. An inborn fear of plants could also help protect against dangers beyond toxins. For instance, some plants have thorns, fine hairs or oils that can damage tissues.

The study was based on a simple experiment that involved placing a plant (basil or parsley), an artificial plant or a fabricated object in front of a baby while the child sat on its mother's lap. No other stimuli were presented in the room to distract the baby. Researchers found that it took about five seconds longer on average for the babies to reach out and touch the plants or artificial plants than it took them to grab any other object.

Questionnaires were also given to the babies' parents about how often their children were exposed to plants, and how often the babies might bear witness to plants being safely handled. It turned out that a baby's familiarity with plants did not seem to affect reaction time. In fact, the babies who commonly witnessed their parents handling plants were actually more averse to touching them.

"What tends to happen when I present this study, is that I have people who have kids come up to me and say, 'Oh yeah, that's right: My kids go for everything, but leave the plants alone,'" said Wertz. "Or they'll say, 'My kids put everything in their mouths, but not the plants.'"

The study might also be a roundabout way of explaining why it's so difficult to get your kids to eat their vegetables. In fact, young children are already known to dislike the bitterness of vegetables, an associated adaptation that may also help protect them from consuming toxic plants.