What makes us ticklish still a mystery

DEAR DOCTOR K: I am a very ticklish person. My husband thinks it’s hilarious how easy it is to make me giggle and squirm. What causes ticklishness?

DEAR READER: Ticklishness is indeed a mysterious phenomenon, and not just for you. To this day, no one has adequately answered the question of what causes it.

Although there isn’t a solid, science-based answer for why we’re ticklish, that hasn’t kept people from researching and speculating. Some of the top theories include these:

• Tickling bonds people. A mom tickles her baby, the baby laughs, the mom smiles, and they share a happy moment together. Similarly, kids who tickle each other may bond over the experience.

• Ticklish spots of the body, such as the abdomen or neck, tend to be more vulnerable. Learning to protect them from tickling as a child may help you protect them from harm.

• Increased skin sensitivity on certain areas of the body develops before birth to encourage a fetus to stay in the healthiest positions in the womb. This centuries-old theory doesn’t seem to have any modern evidence to support it.

The biggest question is whether laughter-associated ticklishness is an uncontrollable reflex, something that is “hard-wired” inside us at birth. Many experts believe that is likely, but others think this kind of ticklishness is something we learn as babies by interacting with our parents and others.

One interesting fact is that you can’t tickle yourself. Once again, there is no convincing scientific data to explain this. If you try to tickle yourself, you’ll know where and when it’s going to happen, and that might cancel out the tickle.

One idea is that, like your startle reflex, laughter-associated tickling requires that you not know it’s coming. Indeed, some studies have shown that people laugh more when they are blindfolded and don’t know where or when they’ll be tickled. However, I’m not sure I believe that theory, either. Even if I’m not surprised, even if I know that someone is trying to tickle me, and then she does it – I still laugh. What about you?