Greetings.

Is there current or past nations, civilizations or uncivilized races or groups that had zero professing behaviors or activities about gods, deities, totally atheists ?

I don’t see how it could happen. Belief is a spectrum and we all have some degree of irrational or illogical behavior.

Even countries that actively discourage(d) religious belief have some fraction of the population engaging in it

35 minutes ago, Externet said:

Greetings.

Is there current or past nations, civilizations or uncivilized races or groups that had zero professing behaviors or activities about gods, deities, totally atheists ?

Yes

9 hours ago, Externet said:

Greetings.

Is there current or past nations, civilizations or uncivilized races or groups that had zero professing behaviors or activities about gods, deities, totally atheists ?

I suppose post-revolutionary France was the first example of a consciously secular state, though it did not try to make its citizens give up personal religious belief. Communist Russia under Lenin and Stalin was probably the first state to teach children atheism and try to stamp out religion. It didn't work of course.

Does ancestor worship count as there are no external gods and the ancestors undoubtedly existed?

All 'groups' of people require some controls to maintain an ordered society.
In the past, this was achieved through religion, and the fear of the wrath of 'gods', and although a lot of the world has shifted towards secularism, governments still have to impose some manner of control to maintain an ordered society. Some are more brutal, some more beneficial.
As a matter of fact, most governments are based on a 'belief' system, as to what is best for society ( or oneself ).
Same difference ...

Since Buddhism has no immortal deities in the Western sense, and the devas are not worshipped as such, much of East Asia can be viewed as atheistic. Though defining a population by what they aren't whether than what they are always struck me as more than a little demeaning.

Mahayaha Buddhists avoid the word worship in describing their veneration of the bodhisattvas, but it seems to me to have some elements of that. Guanyin, for example, the bodhisattva of infinite compassion, is widely prayed to in East Asia for help and safety. Guanyin et al aren't seen as gods, nor as some ultimate spiritual refuge like a supreme being, but they strike me as sort of "god adjacent" in that they are prayed to and seen as guides towards nirvana (which they themselves have put off, so they can help mortal humans). Because of that, I find "atheist" carries maybe the wrong connotation for Buddhist practice when applied in the Western sense. Just saying, you have to be careful with your definition if you apply the term to a Buddhist.

2 hours ago, TheVat said:

Just saying, you have to be careful with your definition if you apply the term to a Buddhist.

Beware of Gautama woo?