Complex adaptive systems can't be understood just at the agent or the collective level.

For example, the bee vs the hive.

If you focus on just optimizing one level you'll create maladaptive outcomes in the other layer.

The system emerges from the interplay of those two levels

Note that this agent vs collective interplay nests, fractally, down to the very bottom of the system.

The hallmark of complex systems is you have to optimize the whole.

If you optimize any one part then you'll create weird problems in other parts of the system.