Approach-avoidance and happiness indicators in natural environments: a preliminary analysis of the Stimulus Preference Coding System.

Two studies assessed the reliability and utility of the Stimulus Preference Coding System (SPCS) to measure approach, avoidance, and happy and unhappy behaviors in persons with developmental disorders. Study 1 took place in an institutional setting. The nine participants were all adults with mental retardation and multiple associated disabilities. Inter-observer reliability ranged from 72% to 100%. Study 2 took place in an after-school setting. The four participants were children diagnosed with autism and mental retardation. Inter-observer agreement ranged from 70% to 91%. Approach and avoidance behaviors were a function of staff person and task. The SPCS may be useful in identifying reinforcers, promoting happiness, analyzing task and staff effects, and clarifying the relationship of stimulus preference to psychopathology.