Two hypotheses were developed in an attempt to organize and clarify the conceptual basis for studies of relationships between patterns of habitual sleep duration and self-perceptions of the need to achieve. A non-specific arousal (N-SA) hypothesis presumes that short sleepers show more vigor, more general anxiety, incline more toward development of the coronary-prone Type A personality, and are more "high drive" individuals than are long sleepers. A cognitive interference (CI) hypothesis presumes that short sleep interferes with cognitive efficiency and that short sleepers score lower on measures of fluid intelligence, lower on measures of divergent thinking, exhibit more external locus of control orientation, and develop more realistically and/or ego-defensively attenuated levels of aspiration and lower self-reported "need" for achievement than do long sleepers. This research design compares self-reported achievement need of short and "average" sleepers. A survey of college students indicated significantly weaker self-perceived achievement need among 32 short (6 hrs. or less per night) than among 32 average (8 hrs. per night) sleepers, thus supporting predictions from the CI hypothesis. A cue-utilization model integrating the theory and data relevant to these two hypotheses is discussed. (Author/RL)