Understanding the human body is a team effort. That's where the Yachtel group comes in.

Researchers at Yachtolt have been delving into the secrets of probiotics for 90 years.

Yacold also partners with nature portfolio to advance gut microbiome science through the global grants for gut health, an investigator-led research program.

To learn more about Yachtolt, visit yawcult.co.

.jp. That's Y-A-K-U-L-T.C-O.J-P. When it comes to a guide for your gut, count on Yacult.

This is Scientific Americans' 60-second science. I'm Erica Barris. Got a minute?

Ever try to get a baby to smile?

It can seem close to impossible.

And then suddenly there it is, that elusive, seemingly joyous grin.

Well, it turns out, those smiles aren't spontaneous.

They're strategic. Researchers have found that when

babies smile, it's for a reason. They want whoever they're interacting with, typically a parent,

to smile back. And they time it just so, a smile here and a smile there. The researchers

call it sophisticated timing. The study is in the journal, plus one. The researchers

enlisted real mothers and infants and quantified their interactions, which fell into four categories.

One, babies wanted to maximize the amount of time smiling at their mothers. Two, they wanted

to maximize the time the mother smiled at them.

Three, they wanted to experience simultaneous smiling.

And four, no smiling at all.

By studying when smiles happens and what the subsequent effect was, the investigators were able to figure out that for mothers, the goal 70% of the time was to be smiling simultaneously. While for babies, 80% of the time, they just wanted their mother smiling at them.

So mothers want the interaction, while babies just want to be smiled at.

So your baby may not be able to feed itself, talk, or even turn over yet.

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