Figure 2. Thayer’s proposed biopsychologic model for evaluating moods based on self-reported measurements of energy and tension levels (27). Research indicates that whereas states of "calm energy," "calm tiredness," and even "tense energy" are all associated with a predominance of positive moods, periods of "tense–tiredness" are relatively unpleasant and associated with a relatively higher frequency of pessimism and other negative cognitions.