The form matters. The plastic in masks is not inhalable, and in all likelihood wearing a mask reduces inhaled plastics like it reduces inhaling of any other solid.

Infants basically ignore strangers or have mild interest in them.

Infant eyesight is not good for distance; their perception is also in its infancy (their eyes detect photons but their brains are still learning to interpret the signals); their attention is correlated more strongly to sound than vision because sound is what they get in the womb.

I mention strangers because the immediate caregivers of infants were generally not wearing masks around them most of the time even during the depths of the pandemic.

Your friend is most likely engaged in motivated reasoning via confirmation bias; they are seeing what they expect and want to see. Infants in general often look spaced out or alarmed. Their facial expressions should not be taken to infer internal emotional state comparable to what an adult feels. Infant brains don’t yet work like adult brains.

In addition, it’s not like COVID-19 is the first time human babies have been exposed to masks. Mask-wearing in public has been normal in some Asian cultures for decades, and of course some Muslim women cover their faces at all times outside the home.

As a parent in the thick of babies exactly at this age and surrounded by other parents in the same situation, I cannot tell the difference between a "covid" baby and any other.

What I can tell you is how much time and effort the parents are putting into the baby, and whether is home-schooled or goes to school/daycare.

First child? They're probably walking early. Third kid? They'll be pushing a year and a half old with barely 5 words in their repertoire and I'll consider them lucky if they can hold themselves upright using a chair for support.

The parents with 3 young kids just don't have the bandwidth to provide the kind of attention that the baby needs.

I essentially think about it this way - consider how much information AlphaGo has to learn with. Now consider how much information your brain processes with only your vision. You think there's gonna be a statistically relevant causation because there's a piece of fabric on the adult's face?

I can't say for certain, but from my daily sampling it's much less than you intuitively would think. Kids are resilient and motivated to learn.

I've got a covid baby, born June 2020. We're lucky enough that she was able to start school at 3 months old, and since then basically every adult she's interacted with (excluding us parents, but including grandparents) has been masked. These days her and her classmates are starting to wear their masks more often, but it's not fully required until she's 2. She seems well adjusted, social, super playful, and loves exploring the world as much as any kid I've ever known.

I also grew up in the era where you were never ever supposed to use your real name or upload pictures of your face to the internet, and have absolute disdain for this weird webcam culture where people insist on seeing each-other's faces while interacting with them.I think the rise in racism and other forms of hatred on the internet ties directly to the increase in people making photographs of themselves central to their identity. I'm actually kind of hoping her generation grows up with less emphasis on appearance. Maybe we have a couple years here with a few less narcissists. Only good things can come out of such developments IMO.

> I have one friend who absolutely swears that "covid babies" are a thing, and that you can spot them from across the room.

I don't dismiss this out of hand, it is at least somewhat plausible to me that less facial exposure might impact infant development. However, I can also probably spot a covid baby at least somewhat reliably across the room, because I'd just look for any baby that's seems like they're less than 2-3 years old, so I'm not certain that being able to do so reveals very much.

Every baby right now is a "covid baby", so of course they're easy to spot

You'd notice it in professional populations, I'd wager.

I also assume it would be a confounding factor in any study that involved masks, if it was a significant effect. "Weird, the group that breathed in asbestos for 20 years without wearing a mask had 90% more lung cancer than the masked group, but 20% less XYZ. Does asbestos exposure prevent XYZ?"

Given the current hubub, you'd think that such studies are the first thing we'd hear about.

It didn't seem to make a difference at all when Scotland and Wales had mask mandates but England didn't, although I've not seen a rigorous analysis of why this was.

Based on what particle size?

Turns out masks are not made of asbestos.

Unsurprisingly, masks safety and effectiveness has been studied extremely extensively.