"2. Chain-indexes, as in chair₁₁ (in a dry attic), chair₁₂ (in a damp cellar) ... chair_1n; Smith₁₁ (under normal conditions) or, say (on the ground), Smith₁₂ (under extreme starvation conditions) or, say (in a plane at extreme altitudes). Smith₁’s reactions are entirely different in many ways under the different conditions.
The role of the chain-indexes is to provide a technique for the introduction of environmental factors, conditions, situations, etc. On the human level, these would include psycho-logical, socio-cultural, etc., factors.
In a world where a given "cause" has or may have a multiplicity of "effects," each "effect" becomes or may become a "cause," and so on indefinitely. As we know from psychiatry, for instance, a single happening to an individual in childhood may start a chain-reaction series, and color and twist his psycho-logical or even psycho-somatic responses for the rest of his life."
— Alfred Korzybski, The Role of Language in the Perceptual Processes.