Research has shown that fetuses can make reflexive facial expressions, including smiling, as early as 24 weeks of gestation, observed through 4D ultrasounds. However, these expressions are not socially driven but rather reflexive responses to stimuli. For example, a study by Durham University found that fetuses exposed to different flavors, such as carrot or kale, displayed laughter-like or crying-like facial expressions. These reactions indicate reflexive neural activity, not emotional or social smiling.
Which is what I said above.
Ehhhhhhhhh kind of. I just wanted to draw the distinction, which probably wasn't clear in my original comment on the video, that there are two categories of smiles - reflex or social. I wanted to clarify that the baby was not smiling in a social manner like you or I would, rather it was a reflex.
No one can know that for sure, unless the study uses a non-intrusive encephalogram.
Smiling is a human evolutionary trait, and while it is true it can be a reflex, it’s mainly used for social interactions.
For example, a person that doesn’t like dogs will never smile a them.