Understanding systems theory

So, if you look at the behaviour of the individual, how can you predict the behvaiour of the whole? Most people tend to use the framework of things 'averagning out' or 'cancelling each other' or 'one behaviour will be magnified', etc.
But if you look at an ant's colony, the colony as a whole shows far more complicated behavior than an individual ant. If you merely add the behavior of an individual ant, the resultant colony does not look like an actual colony.
Similarly, an individual neuron only knows how to interact with the neighbouring neurons. Yet the resulting network produces the human brain and its remarkable intelligence.
I believe the word used to described this is 'synergy'. Has anyone investigated this issue further?

What conditions in a system lead to the emergence of synergy? This is the million $ question I will be investigating this year.

Conversely, how can u use system's theory's principles in marketing? Like, if associations are 'risk-aversive', would the set of associations be merely risk aversive or possibly more, like an ant colony?

I gotto explore systems theory in further detail and develop this v relevant and impt framework.