Image of a happy baby in a crib

By Mishal Ali Zafar

When you have a newborn, they don’t do much other than sleeping, feeding, and pooping. But as they get older, and become more aware of their surroundings, they put out some of the biggest rewards a parent can get from their child — smiles and laughter. There’s this amazing feeling you get inside when you see your child giggle, so naturally you want to see them laughing more often, even if that involves a tickle here or there. You know your motivation for tickling a baby, but what happens in a baby’s brain when they’re getting tickled?

Romper reached out to Eric Morley, M.D., a pediatrician at MemorialCare Medical Group in Aliso Viejo, California who says when it comes to figuring out what kind of brain action tickling prompts in your baby, the short answer is that no one really knows for sure. He says that scientists and philosophers have been speculating about tickling for about 2,000 years, asking such questions as “What is actually happening in your body when you are tickled?” and “Why can’t we tickle ourselves?”

"We often laugh when tickled,” says Morley, “and it is not exactly clear whether this is a result of the sensation of being tickled or a conditioned response evolving from repeated playful behavior associated with tickling and laughter of the tickler.”

Morley explains that generally babies do not begin to laugh until around 4 months of age, and their laughter in response to being tickled may not begin until around 6 months. He notes that new research suggests that prior to 6 months, babies may not associate the tickling sensation with the person who is smiling, laughing, and tickling them. “Rather, they just feel the 'tickle' sensation,” adds Morley, “but don’t really understand its origin.” He says that more research is definitely needed to fully understand the complexity of a tickle.

Why is tickling in a baby so hard to understand? Trung Tristan Truong, M.D., a pediatrician at Saddleback Medical Center in Laguna Hills, California tells Romper that assessing a baby’s response to touch or tactile sensory can be really challenging. He suspects that a baby’s response to being tickled depends on the context involved, along with the level of development of the baby. “A younger infant may not necessarily enjoy or dislike being tickled,” explains Truong, “due to perhaps relative lack of other sensory awareness, as well as an immature social connection.” He says that the tickle may just make the baby respond by eliciting a motor (movement) response or an arousal response.

Truong says that as infants grow and mature, their responses to being tickled should change due to their increased alertness of the other sensory systems, including their visual and auditory senses. As they develop their senses, they may like or dislike the tickle stimulus, explains Truong, depending on the circumstance or baby’s mood (happy, hungry, tired etc). “A baby who is content and playful and is being tickled by a parent who is expressing affection and making cute sounds will more likely enjoy the experience and result in laughter as the baby perceives love and caring from the parent.”

So while there may not be a definitive answer as to what goes on in a baby’s brain ever, you will be able to tell by their reaction if they like it or not. As a parent you should be able to gauge your baby’s comfort level, and if you feel the tickling is making them uncomfortable or scared, you may want to stop. As they get older, they may begin understanding the concept and motivation behind the tickling, allowing them to laugh and giggle or even tell you when to stop.