’Contagious’ spreading of behaviours through imitation, is known as

The correct option is Ripple effect.

Explanation:

The "ripple effect" refers to a phenomenon where an initial disturbance, behavior, or action spreads outward to affect an increasingly larger circle of individuals or situations, much like ripples expanding across the surface of water when a pebble is dropped into it.

In social science and psychology, this term is specifically used to describe the contagious spreading of behaviors, attitudes, or emotions through imitation and social influence. When one person adopts a behavior (such as a specific style, reaction, or habit), others observe and imitate it, creating a chain reaction that propagates through a group or community.

Let's briefly look at why the other options are incorrect:
1. Norm effect: While norms influence behavior, this term does not specifically describe the spreading or cascading process of behavioral imitation.
2. Random effect: This refers to statistical variability or unpredictable occurrences, rather than the structured, copy-cat transmission of behavior.
3. Scripted effect: This implies pre-planned, rehearsed, or automated behaviors guided by a schema or script, not the spontaneous, contagious spread of imitation.