>Large groups cannot “process” anything; individual humans do that.

That's too reductionist. Ultimately "humans" do it, like ultimately atoms do chemical interactions, but there are absolutely "group dynamics", they have been studied quite a lot, and an "individual" in a group context can operate totally different (and has different options, tradeoffs, etc) than an individual alone.

A very basic example: a human can forget X.

A group, on the other hand, has a collective memory (institutional memory), and even if an individual forgets, it takes many individuals forgetting to erase something.

Groups absolutely have an emergent consciousness, whether it is based on consensus or tyranny. Even a "human self" is ultimately a symbolic, higher-order complex formed from separate, often competing cognitions. In a very similar way, a group forms a mind and thinks, even if only one person is calling the shots: your conscious awareness will likely tend towards the cognitions created by your core beliefs, but that doesn't mean the others aren't there. They're just less conscious.

No. Groups process things, but you must frame your question in terms of things you can measure about a group.

An individual is a system; using your own logic it is inappropriate to talk about how a human feels. One must talk about each individual neuron and cell.

That's a very reductive take on what OP said. We're talking about social science, not biology here, so the individual is the atomic unit. Individual=Indivisible.

You can talk about tendencies across a group, but cognition is inherently done on an individual level, even accounting for network effects.

OTOH if what you're saying is that large groups of people can tend to share the same psychoses, well, that's a totally different statement.

>We're talking about social science, not biology here, so the individual is the atomic unit.

Not every observable property is available on the "atomic unit". Some only appear (emergent properties) after the association and observation of many such units, that is, in a group.

In particle-terms, a single atom can't be a crystal.

Or a living organism.

But there are absolutely things that happen at the level of crystal forms or living organisms, etc, that don't happen at the single atom level.

>You can talk about tendencies across a group, but cognition is inherently done on an individual level, even accounting for network effects.

Only in a crude understanding of cognition.

> Not every observable property is available on the "atomic unit". Some only appear (emergent properties) after the association and observation of many such units, that is, in a group.

Name a property of the group that's more than a sum of the properties of the individual. Population, for instance.

The crystal analogy, again, isn't helpful because we're talking about social science, not physics.

>Name a property of the group that's more than a sum of the properties of the individual

An individual cannot exhibit groupthink without a group. They also can't have in-group bias without a group. Both important properties in group dynamics.

Roles and positions within a group are similar to the "crystal example" as well, with groups forming particular patterns under specific pressures, patterns impossible to the individual (e.g. an individual is not a "protest march" or a political party).