In 1972, Nickolas Cottrell came up with Evaluation Apprehension Theory. This theory also explains the evaluative pressure as the source of increased productivity in presence of others rather than the arousal response identified by Zajonc. The theory assumes that people learn from experience that the source of most reward and punishments are other people they interact with. Therefore, people associate social situations with evaluation and hence, feel apprehensive in presence of other people. The evaluation apprehension improves performance on simple tasks but is debilitating in more complex and difficult tasks.