Emergence isn't necessarily about smaller to bigger, although it is a property of groups or interactions. It is something that happens in intermediate states between absolutely chaotic behaviour and rigidly ordered systems. It can occur from very small scales, like whirlpools/vortices, or crystal nuclei, or ripples, beginning with half a dozen molecules, but also capable of scaling.
In general, reductionism is very successful. We can use the simplest effective elements of a system, to predict it's behaviours. Units of crystal lattices, or kinetics of gas molecules, can predict bulk properties. Sometimes though, we find feedbacks that cause dynamic states to stabilise, eg chemical buffering, where pH is stabilised by equilibria between compounds - this can occur with just one set of the molecules involved, though it also scales up to a bulk property.
Emergentism is a mode of explanation, in terms of group or system properties. So it's opposite is the reductionist mode of explanation. They both concern bulk properties of systems where there there are groups of similar constituents, ie science.
It sounds like you might be asking about uniqueness, or idiosyncrasy. Or maybe how degrees of freedom of constituents can be suppressed in group behaviour, like how superconductivity occurs below a certain temperature when the thermal motion stops it affecting bulk properties (electrons stop coupling to phonons).
It is very common for large groups of objects to be predictable, even when an individual element is not. An example is modelling traffic as though it was a gasmodelling traffic as though it was a gas. This is kind of the opposite of emergent behaviour, where elements known to behave completely unpredictably, operate within constraints (roads) and have limited interactions (communication limited to vehicle position, indicators, lights). Uniqueness or unpredictability is then suppressed, resulting in ordered behaviour.
What motivated your question?