The present study explores how affectivity and abstraction value influences the span of attention of normal and retarded population. Five intellectual functioning groups were chosen, six in each (N = 30), from both sexes, age of 11 - 23 (mean age 17.36) years from the urban hospitals and educational institutions. For standardization of stimulus materials and controlling of extraneous variables three preliminary experiments were done. A repeated measure experimental design was followed in the main study. Result shows attention span tends to decrease with an increment in abstraction level in the lower range of intellectual ladder. Affective loading in stimulus materials does not enhance the span of attention, per se it inhibits cognition. The result was interpreted in the light of behavioural observation during the experimental conditions as well as the obtained statistical output. Overall analysis revealed that the persons with moderate retardation scored better in attention span in comparison to mild retarded group where average group scored highest. So, the result of span of attention did not follow the ladder of intellectual impairment. The causal attribution on result was interpreted in terms of environmental distraction and the lack of basic cognitive need of the moderately retarded persons which inversely facilitated better attention span as their attention span remains unaffected by distraction. The result is helpful to design the learning materials for the specific intellectual group.