Emergence

Chapter 2 endnote 20, from How Emotions are Made: The Secret Life of the Brain by Lisa Feldman Barrett.
Some context is:

Problems with reverse engineering are a clue that you are dealing with emergence (Barrett 2011a), i.e., that a system has properties beyond the sum of its components.

An emergent property is a system-level property that is dependent on the organization of the system’s more basic elements or parts but cannot be reduced to them. For example, the chewiness of bread is an emergent property, because it depends on flour, water, yeast, and salt but cannot be reduced to these basic ingredients.

Emergence typically arises in a complex system, in which system-level properties are produced by the collective behavior of a large assembly of simpler elements. These system-level properties are:

Irreducible

They are distinct in existence from the basic elements that give rise to them.

Unpredictable

The starting values, context, and the interactions between basic elements produce probabilistic outcomes.

Conceptually novel

They can be described effectively only by introducing a new concept does not exist at the lower level of the basic elements. (That is the concept is ontologically new with respect to the more basic elements.)

For a discussion of emergence in theories of emotion, see this reference.